Conditions

• CHRONIC KIDNEY DISEASE
• GLOMERULAR DISEASE
• POLYCYSTIC KIDNEY DISEASE
• OEDEMA (BODY SWELLING)
• PROTEIN IN THE URINE (PROTEINURIA)
• BLOOD IN THE URINE (HAEMATURIA)
• KIDNEY STONES
• HIGH BLOOD PRESSURE (HYPERTENSION)
• DIABETIC KIDNEY DISEASE

CHRONIC KIDNEY DISEASE

Chronic kidney disease (CKD) is a progressive loss in kidney function over a period of months or years leading to inability of the kidneys to remove waste and excess water from the body. It is usually detected by blood and urine tests. CKD does not usually cause symptoms until it reaches an advanced stage. If not treated kidney failure can be life-threatening.

The most common causes of chronic kidney disease are diabetes and high blood pressure.

Diseases and conditions that commonly cause chronic kidney disease include:

• Type 1 or type 2 diabetes
• High blood pressure
• Glomerulonephritis (gloe-mer-u-lo-nuh-FRY-tis), an inflammation of the kidney's filtering units (glomeruli)
• Interstitial nephritis, an inflammation of the kidney's tubules and surrounding structures
• Polycystic kidney disease
• Prolonged obstruction of the urinary tract, from conditions such as enlarged prostate, kidney stones and some cancers
• Vesicoureteral (ves-ih-koe-yoo-REE-ter-ul) reflux, a condition that causes urine to back up into your kidneys
• Recurrent kidney infection, also called pyelonephritis (pie-uh-lo-nuh-FRY-tis)

CHRONIC KIDNEY DISEASE RISK FACTORS

Are you at risk?

• Do you have high blood pressure?
• Do you suffer from diabetes?
• Do you have a family history of kidney disease?
• Are you overweight?
• Do you smoke?
• Are you over 50 years?

If you have answered yes to one or more of these questions, you should discuss with your doctor. Early chronic kidney disease has no sign or symptoms. You can help delay or prevent kidney failure by treating kidney disease early.

Detection of Kidney Disease

Detecting CKD is simple and requires a blood to measure creatinine (a waste product in your blood that comes from muscle activity) and estimate Glomerular Filtration Rate (eGFR) to estimate your overall kidney function and urine test to detect excess protein in the urine.

Primary prevention

Kidney diseases are usually silent and is important you reduce the risk of developing kidney disease by:

• Keep fit and active
• Keep regular control of your blood sugar level
• Monitor your blood pressure
• Eat healthy and keep your weight in check
• Maintain a healthy fluid intake
• Do not smoke
• Do not take over-the-counter pills on a regular basis

Secondary prevention

Identifying early stages of CKD is key in delaying or preventing kidney failure and protect against both kidney and heart disease. Measures implemented include:

• Reduction of high blood pressure, the lower the blood pressure (within the normal range), the slower the kidney function decline
• Specific medications to reduce proteinuria as well as lower blood pressure – angiotensin converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs)
• Reduce salt intake to lower blood pressure
• Control of glucose
• Smoking cessation
• Increase of physical activity
• Control of body weight

What you should ask your doctor?

Here are some key questions that you can ask your doctor:

• What is my GFR?
• What is my urine albumin result?
• What is my blood pressure?
• What is my blood glucose (for people with diabetes)?

CHRONIC KIDNEY DISEASE COMPLICATIONS

Most people with chronic kidney disease (CKD) do not have symptoms until the kidney function is severely impaired. Most people still make a normal or near-normal amount of urine despite the severity of the kidney failure but the urine does not contain sufficient amounts of the body's waste products.

Signs of advancing CKD include tiredness, decreased appetite, nausea, vomiting, increased sleepiness, swollen ankles, shortness of breath, blood in the urine and foamy urine (sign of presence of protein) and difficulty concentrating, drowsiness, seizures, or coma

DIAGNOSIS

The following tests are usually requested to diagnosis chronic kidney disease:

Kidney function tests

A blood sample for the creatinine is usually obtained. Creatinine is a substance derived from the turnover of the muscles in the body. The level of the creatinine in the blood is then used to calculate the glomerular filtration rate (GFR) which gives an approximate measure of the number of functioning nephrons (kidney cells).

Urine tests

The presence of albumin or protein in the urine (called albuminuria or proteinuria) is a marker of kidney disease. Even small amounts of albumin in the urine may be an early sign of CKD in some people, particularly those with diabetes and high blood pressure.

Imaging studies

Imaging tests may be recommended to determine if there are any obstructions (blockages) of the urinary tract, kidney stones, or other abnormalities. Kidney ultrasound is usually the initial test.

Kidney biopsy

In a kidney biopsy, a small piece of kidney tissue is removed and examined under a microscope. The biopsy helps to identify abnormalities in kidney tissue that may be the cause of kidney diseases.

TREATMENT

Treatment options vary, depending on the cause. Reversible cause if early identified can prevent CKD.  In most cases, the main goal of treatment is to prevent progression of CKD to complete kidney failure. The best way to do this is to diagnose and control the underlying cause. But kidney damage can continue to worsen even when an underlying condition, such as high blood pressure, has been controlled.

High blood pressure (Hypertension)

Hypertension is present in 80 to 85% of people with CKD. Maintaining good blood pressure control is the most important factor in retarding the rate of progression of CKD. A medication called an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker has been shown to reduce blood pressure and to preserve kidney function. High blood pressure medications can initially decrease kidney function and change electrolyte levels, so you may need frequent blood tests to monitor your condition. A water pill (diuretic) and a low-salt diet may also be recommended.

Anaemia

Anaemia is common in patients with advanced CKD. This occurs because the failing kidneys produce reduced amounts of a substance called erythropoietin (uh-rith-roe-POI-uh-tin). Erythropoietin supplements sometimes with added iron aid in production of more red blood cells, which may relieve fatigue and weakness associated with anaemia.

Medications to relieve swelling

People with chronic kidney disease may retain fluids. This can lead to swelling in the legs, as well as high blood pressure. Medications called diuretics can help maintain the balance of fluids in your body.

Dietary changes

Diet modification may be recommended to control some of the complications of CKD.

Salt

Salt restriction is common to control the blood pressure. Avoid products with added salt. Lower the amount of sodium you eat each day by avoiding products with added salt, including frozen meals, canned soups, fast foods and foods with added salt include salty snack foods, canned vegetables, and processed meats and cheeses.

Protein

Protein restriction in the diet is occasional recommended to slow the progression of CKD. However, it is not clear if the benefits of protein restriction are worth the difficulty of sticking to a low protein diet. High-protein foods include lean meats, eggs, milk, cheese and beans. Low-protein foods include vegetables, fruits, breads and cereals.

Potassium

Some people with CKD develop a high blood potassium level, which can interfere with normal cell function. This is frequently treated with a diuretic. Measures to prevent high potassium might also be recommended, including a low potassium diet and avoiding medicines that raise potassium levels. High-potassium foods include bananas, oranges, potatoes, spinach and tomatoes. Examples of low-potassium foods include apples, cabbage, carrots, green beans, grapes and blueberries. Be aware that many salt substitutes contain potassium, so you should avoid them if you have kidney failure.

Phosphate

Phosphate is a mineral that helps to keep the bones healthy. As the CKD progresses, the body starts to retain phosphate. This is usually treated with Dietary phosphate restrictions and medications that prevent phosphate from being absorbed in the digestive tract.

Medications to protect your bones

Calcium and vitamin D supplements may be required to prevent weak bones and lower your risk of fracture. You may also take medication to lower the amount of phosphate in your blood, to protect your blood vessels from damage by calcium deposits (calcification).

Cholesterol and triglycerides

High cholesterol and triglyceride levels are common in people with kidney disease. High triglycerides can lead to heart attack. Dietary modifications and medicines called statins are used to treat high triglyceride and cholesterol levels.

Sexual function

Men and women with advanced CKD often have difficulties with sexual function and infertility. Over 50 percent of men with end-stage kidney disease have difficulties with erection and decreased sex drive. Women often have disturbances in the menstrual cycle and fertility, usually leading to a stop in menstrual periods. Decreased sex drive may also occur in women.

PREPARING FOR DIALYSIS

Some people with CKD progressively worsen over time and will eventually need dialysis. There are two types of dialysis: hemodialysis and peritoneal dialysis. Kidney transplantation is also an option for some people with CKD.

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GLOMERULAR DISEASE

Many diseases affect kidney function by attacking the glomeruli, the tiny units within the kidney where blood is cleaned. Glomerular diseases include many conditions with a variety of genetic and environmental causes.

How do glomerular diseases interfere with kidney function?

Glomerular diseases damage the glomeruli, letting protein and sometimes red blood cells leak into the urine. Sometimes a glomerular disease also interferes with the clearance of waste products by the kidney, so they begin to build up in the blood. Furthermore, loss of blood proteins like albumin in the urine can result in a fall in their level in the bloodstream. In normal blood, albumin acts like a sponge, drawing extra fluid from the body into the bloodstream, where it remains until the kidneys remove it. But when albumin leaks into the urine, the blood loses its capacity to absorb extra fluid from the body. Fluid can accumulate outside the circulatory system in the face, hands, feet, or ankles and cause swelling.

What are the symptoms of glomerular disease?

The signs and symptoms of glomerular disease include:

• Albuminuria: large amounts of protein in the urine
• Haematuria: blood in the urine
• Reduced glomerular filtration rate: inefficient filtering of wastes from the blood
• Hypoproteinemia: low blood protein
• Oedema: swelling in parts of the body

What causes glomerular disease?

A number of different diseases can result in glomerular disease. It may be the direct result of an infection or a drug toxic to the kidneys, or it may result from a disease that affects the entire body, like diabetes or lupus. Many different kinds of diseases can cause swelling or scarring of the nephron or glomerulus. Sometimes glomerular disease is idiopathic, meaning that it occurs without an apparent associated disease.

Nephrotic syndrome

People with nephrotic syndrome have protein in the urine (proteinuria) but, often, little to no blood in the urine (haematuria). Kidney function may worsen as nephrotic syndrome progresses.

How is glomerular disease diagnosed?

Urine tests

The urinalysis may show red blood cells (which are seen when there is damage or inflammation in the glomeruli), white blood cells (which can indicate inflammation), or increased protein levels (which is an indicator of glomerular damage).

Blood tests

Blood tests are used to measure the level of creatinine which become elevated when the kidneys are damaged and are not filtering properly. Blood tests may also be used to diagnose underlying medical conditions (such as diabetes, lupus, or certain infections).

Imaging tests

An ultrasound of the kidney is frequently recommended if glomerular disease is suspected, primarily to rule out other causes of blood in the urine and/or decreased kidney function. The ultrasound can also measure the size of the kidneys, which can provide a clue as to the duration of the kidney disease.

Kidney biopsy

A kidney (renal) biopsy may be needed to definitively determine the cause of glomerular disease in patients that cannot be diagnosed by blood tests or imaging tests alone. A separate topic review discusses renal biopsy.

GLOMERULAR DISEASE TREATMENT

The treatment of glomerular disease depends upon the type (acute or chronic), the underlying cause, and the severity of associated signs and symptoms. Some forms of glomerular disease, such as that caused by infection, improve after the infection is treated. Other types of glomerular disease may require treatment with immune suppressant medications, such as steroids. Some forms of glomerular disease do not require treatment, while others do not respond to any therapy.

GLOMERULAR DISEASE COMPLICATIONS

Some types of glomerular disease are associated with complications, including high blood pressure, acute or chronic kidney failure, and nephrotic syndrome.

High blood pressure

High blood pressure can develop in people with glomerular disease due to kidney damage and build up of waste products and excess fluid in the bloodstream.

Acute kidney injury

Acute kidney injury (failure) is associated with acute glomerulonephritis. Temporary haemodialysis may be needed to remove waste products and excess fluids.

Chronic kidney disease

If kidney function continues to worsen, dialysis or kidney transplantation may be needed to perform the normal functions of the kidneys.

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POLYCYSTIC KIDNEY DISEASE

Polycystic kidney disease (PKD) is a condition in which the kidneys become enlarged with multiple cysts. The cysts replace the kidney tissue and can sometimes lead to kidney failure and the need for dialysis or kidney transplantation. There are two types of PKD. Autosomal dominant polycystic kidney disease (ADPKD) occurring in approximately 1: 400 to 1000 people. Autosomal dominant means that each child of an affected parent has a 50 percent chance of inheriting the disease. In addition, autosomal dominant means that it does not skip generations (ie, if a patient with the disease does not pass it along to one of his or her children, then the disease disappears from that family and grandchildren cannot inherit the disease). The other form of PKD is autosomal recessive polycystic kidney disease (ARPKD) which is uncommon and is typically diagnosed in infancy or in utero. The estimated incidence is approximately 1: 20,000 people. Autosomal recessive means that the mutated gene must be present in both parents, who, because they carry one abnormal gene, are considered carriers. When both parents are carriers (each having one abnormal and one normal gene), then there is a 25 percent chance that each child will inherit an abnormal gene from both parents and have the disease.

Approximately 85 percent of families with autosomal dominant polycystic kidney disease (ADPKD) have a mutation in the PKD1 gene, located on chromosome 16; these people have PKD1 disease. The remaining 15 percent have a mutation in the PKD2 gene on chromosome 4; this is called PKD2 disease. In some cases, it is not possible to detect which gene is mutated. PKD2 disease is milder; therefore, it often presents later in life and is sometimes not diagnosed at all. Thus, it is likely that more than 15 percent of all people with ADPKD have PKD2 disease.

Kidney failure occurs at an earlier age in PKD1 patients; the average age of end-stage renal disease (that is, needing dialysis or a transplant) is approximately 55 years in PKD1 versus 74 years in PKD2 patients.

COMPLICATIONS OF PKD

Autosomal dominant polycystic kidney disease (ADPKD) often leads to progressive kidney failure, due primarily to continued enlargement of the cysts and replacement of normal kidney tissue. Other problems involving the kidney can occur, including high blood pressure, Flank and abdominal pain, kidney infection,

ASSOCIATION CONDITIONS OUTSIDE OF THE KIDNEY

A variety of conditions outside the kidney can occur in people with autosomal dominant polycystic kidney disease (ADPKD). These conditions are intracranial aneurysm, liver cysts, heart valve disease abnormalities and abdominal wall hernias.

POLYCYSTIC KIDNEY DISEASE DIAGNOSIS

 It is usually easy to diagnose autosomal dominant polycystic kidney disease (ADPKD) in people who develop flank or abdominal pain and in those who have a family history of ADPKD. An imaging study, such as an ultrasound, is recommended as the first diagnostic test and may reveal multiple cysts on both kidneys. Kidneys are usually enlarged, but may be of normal size in the early stages. Cysts may also be seen in the liver, pancreas, and spleen.

POLYCYSTIC KIDNEY DISEASE TREATMENT

Autosomal dominant polycystic kidney disease (ADPKD) leads to kidney failure due to continued enlargement of the cysts in the majority of patients, typically by the sixth decade of life. Treatment focuses on slowing the progression of kidney failure and treating the associated features of the disease, such as high blood pressure, kidney infections or kidney stones and flank or abdominal pain.

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OEDEMA (BODY SWELLING)

Oedema is the medical term for fluid retention in the body and commonly affect the following sites:

• The lower legs or hands (called peripheral oedema)
• Abdomen (called ascites) causing increased size of the abdomen
• Chest (pulmonary oedema if in the lungs, and pleural effusion if in the space surrounding the lungs) leading to Difficulty breathing.

CONDITIONS ASSOCIATED WITH OEDEMA

A number of different problems can cause oedema.

Chronic venous disease

A common cause of oedema in the lower legs is chronic venous disease, a condition in which the veins in the legs cannot pump enough blood back up to the heart because the valves in the veins are damaged. This can lead to fluid collecting in the lower legs, thinning of the skin, and, in some cases, development of skin ulcers.

Oedema can also develop as a result of a blood clot in the deep veins of the lower leg. In this case, the oedema is mostly limited to the feet or ankles and usually affects only one side (the left or right).

Pregnancy

Pregnant women retain extra fluid. Swelling commonly develops in the hands, feet, and face, especially near the end of a normal pregnancy. Swelling without other symptoms and findings is common and is not usually a sign that a complication.

Monthly menstrual periods

Oedema in women that occurs in a cyclic pattern (usually once per month) can be the result of hormonal changes related to the menstrual cycle. This type of oedema is common but does not require treatment because it resolves on its own.

Drugs

Oedema can be a side effect of a variety of medications, including some oral diabetes medications, high blood pressure medications, non-prescription pain relievers (such as ibuprofen), and oestrogens.

Kidney disease

The oedema of kidney disease can cause swelling in the lower legs and around the eyes.

Heart failure

Heart failure is due to a weakened heart, which impairs its pumping action. Heart failure can cause swelling in the legs and abdomen, as well as other symptoms. Heart failure can also cause fluid to accumulate in the lungs (pulmonary oedema), causing shortness of breath.

Liver cirrhosis

 Cirrhosis is scarring of the liver from various causes, which can obstruct blood flow through the liver. People with cirrhosis can develop pronounced swelling in the abdomen or in the lower legs.

Travel

Sitting for prolonged periods, such as during air travel, can cause swelling in the lower legs. This is common and is not usually a sign of a problem.

Angioedema

Reactions to some medications and some inherited disorders can cause fluid to leak out of the blood vessels into surrounding tissues (angioedema). This can cause rapid swelling in the face, lips, tongue, mouth, throat, voice box, limbs, or genitals. Symptoms may include hoarse voice, throat tightness, and difficulty swallowing. Swelling of the throat can interfere with breathing and may be life threatening.

Lymphoedema

Surgical removal of lymph nodes for the treatment of cancer (most commonly breast cancer) can cause swelling of a limb or limbs with thickening of the skin on the side of the surgery. Swelling of both legs because of lymph problems can also be an inherited condition that becomes apparent in childhood or young adulthood.

TREATMENT

Treatment of oedema depends on the cause and not all types of oedema require treatment e.g in pregnancy or during menstrual cycles.  Reducing the amount of salt (sodium) in diet, use of a diuretic to eliminate excess fluid and using compression stockings and elevating the legs may also be recommended.

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PROTEIN IN THE URINE (PROTEINURIA)

TYPES OF PROTEINURIA

Proteinuria can be divided into three categories: transient (intermittent), orthostatic (related to sitting/standing or lying down), and persistent (always present).

Transient proteinuria — Transient (intermittent) proteinuria is by far the most common form of proteinuria. Transient proteinuria usually resolves without treatment. Stresses such as fever and exercise may cause transient proteinuria.

Orthostatic proteinuria — Orthostatic proteinuria occurs when one loses protein in the urine while in an upright position but not when lying down. It occurs in 2 to 5 percent of adolescents but is unusual in people over the age of 30 years. The cause of orthostatic proteinuria is not known. Orthostatic proteinuria is not harmful, does not require treatment, and typically disappears with age.

Orthostatic proteinuria is diagnosed by obtaining a split urine collection. This requires collecting two urine samples: one while you are standing or sitting up (usually during the day) and another after you have been sleeping for several hours (eg, first thing in the morning).

Persistent proteinuria — In contrast to transient and orthostatic proteinuria, persistent proteinuria occurs in people with underlying kidney disease or other medical problems. Examples include:

• Kidney diseases
• Diseases that affect the kidney, such as diabetes mellitus
• Diseases that cause the body to overproduce certain types of protein

PROTEINURIA DIAGNOSIS

Proteinuria is diagnosed by testing the urine often with a dipstick test followed by a quantitative measurement of the protein in the laboratory. If proteinuria is confirmed then a blood Blood test is required to assess the kidney function and other test to exclude inflammation as the cause for the proteinuria.

A Kidney biopsy may be required to reach the correct diagnosis and plan management.

TREATMENT

Transient and orthostatic proteinuria are not harmful conditions, and no specific treatment is needed.

Patients with persistent low-grade proteinuria that is not related to decreased kidney function or a systemic disease typically have no long-term complications, even if untreated. Many nephrologists use an antihypertensive drug, such as an angiotensin-converting enzyme (ACE) inhibitor, to reduce or eliminate proteinuria.

In patients with persistent high-grade proteinuria who have decreased kidney function, the underlying condition is usually treated.

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BLOOD IN URINE (HAEMATURIA)

Haematuria is the presence of red blood cells in the urine. Large numbers of red blood cells turn the urine red: this is called visible haematuria (VH); also called macroscopic haematuria or gross haematuria macroscopic haematuria.

Non-visible haematuria (NVH): also called microscopic haematuria or dipstick-positive haematuria and is further classified as:

• Symptomatic non-visible haematuria (s-NVH) - associated symptoms include voiding lower urinary tract symptoms (LUTS): hesitancy, frequency, urgency, dysuria.
• Asymptomatic non-visible haematuria (a-NVH) - incidental detection in the absence of LUTS or upper urinary tract symptoms.

Significant haematuria is defined as:

• Any single episode of VH.
• Any single episode of s-NVH (in absence of urinary tract infection (UTI) or other transient causes).
• Persistent a-NVH (in absence of UTI or other transient causes). Persistence is defined as 2 out of 3 dipsticks positive for NVH.

What are the facts about blood in the urine?

• The commonest cause of blood in the urine in the UK is infection (cystitis)
• Proven blood in the urine, whether visible or non-visible (found on a urine test), should always be investigated
• 1 in 5 adults with visible blood in the urine and 1 in 12 adults with non-visible blood in the urine are subsequently discovered to have bladder cancer
• Children with blood in the urine rarely have cancer - they usually have infection in the bladder or kidney inflammation (nephritis).
• A "one-off" finding of a small trace of blood in the urine on routine testing may not be significant
• Some drugs (e.g. rifampicin, nitrofurantoin) and foodstuffs (e.g. beetroot) can turn the urine red and mimic blood in the urine

Red flag symptoms

• Painless macroscopic haematuria
• Symptomatic microscopic haematuria in absence of UTI
• Age >50 years
• Abdominal mass on examination

Common causes of blood in urine

These include:

• a bladder infection (such as cystitis) – which typically also causes a burning pain when you urinate
• a kidney infection – which may also cause a high temperature and pain in the side of your tummy
• kidney stones – which may be painless, but can sometimes block one of the tubes coming from your kidneys and cause severe tummy pain
• urethritis – inflammation of the tube that carries urine out of the body (urethra); it's often caused by a sexually transmitted infection (STI) such as chlamydia
• an enlarged prostate gland – this is a common condition in older men and nothing to do with prostate cancer; an enlarged prostate gland will press on the bladder and may also cause problems such as difficulty urinating and a frequent need to urinate
• bladder cancer – this usually affects adults aged over 50 and can also cause you to urinate more often and more urgently, as well as pain when urinating
• kidney cancer – this also usually affects adults aged over 50, and can cause persistent pain below your ribs and a lump in your tummy
• prostate cancer – this is usually only seen in men aged over 50 and usually progresses very slowly; other symptoms can include needing to urinate more frequently and urgently, and difficulty emptying your bladder

Investigations and management

Transient causes that need to be excluded before establishing the presence of significant haematuria are UTI, exercise-induced haematuria or, rarely, myoglobinuria, and menstruation.

• All children with haematuria should be referred.
• All definite haematuria, whether VH or NVH, requires investigation to exclude serious underlying conditions, especially urinary tract neoplasm.[1]
• Patients on anticoagulants should also be investigated. Anticoagulants are more likely to provoke, rather than be the cause of, haematuria.

Initial investigations for a patient with s-NVH and persistent a-NVH

• Exclude UTI and/or other transient cause.
• Plasma creatinine and estimated glomerular filtration rate (eGFR).
• Measure proteinuria: send urine for protein:creatinine ratio (PCR) or albumin:creatinine ratio (ACR) on a random sample (according to local practice). 24-hour urine collections for protein are rarely required. An approximation to the 24-hour urine protein or albumin excretion (in milligrams) is obtained by multiplying the ratio (in mg/mmol) x 10.
• Measurement of blood pressure.

Other initial investigations

These may include:

• FBC (anaemia) and clotting screen.
• Urine red cell morphology: dysmorphic erythrocytes suggest a renal origin.
• Cytological examination of urine.

Indications for urological referral

Direct referral to urology for further investigation is required for:

• All patients with visible haematuria; a nephrology referral may be considered more appropriate if glomerulonephritis is suspected.
• All patients with s-NVH (any age).
• All patients with a-NVH aged ≥40 years.

Indications for nephrological referral

• For patients who have had a urological cause excluded or have not met the referral criteria for a urological assessment, a referral to nephrology should be considered.
• Evidence of declining GFR (by greater than 10 ml/minute at any stage within the previous five years or by greater than 5 ml/minute within the previous one year).
• Stage 4 or 5 chronic kidney disease (eGFR less than 30 ml/minute).
• Significant proteinuria (ACR 30 mg/mmol or higher, or PCR 50 mg/mmol or higher).
• Isolated haematuria (ie in the absence of significant proteinuria) with hypertension in those aged younger than 40 years.
• Visible haematuria coinciding with intercurrent (usually upper respiratory tract) infection.

Long-term monitoring of patients with haematuria

Patients not meeting criteria for referral or who have had negative urological or nephrological investigations (including all of: eGFR 60 ml/minute or higher, and ACR less than 30 mg/mmol or PCR less than 50 mg/mmol, and blood pressure less than 140/90 mm Hg) need long-term monitoring due to the uncertainty of the underlying diagnosis. Patients should be monitored for the development of:

• Voiding LUTS.
• Visible haematuria.
• Significant or increasing proteinuria.
• Progressive renal impairment (falling eGFR).
• Hypertension (the development of hypertension in older people may have no relation to the haematuria).

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KIDNEY STONES

Kidney stones often have no definite, single cause, although several factors may increase your risk. Kidney stones form when your urine contains more crystal-forming substances such as calcium, oxalate and uric acid. Stones can also form if these substances are at normal levels, especially if the amount of urine made each day is low. The substances form crystals, which become anchored in the kidney and gradually increase in size, forming a kidney stone.

Types of kidney stones

• Calcium stones. Most kidney stones are calcium stones, usually in the form of calcium oxalate. Oxalate is a naturally occurring substance found in food. Some fruits and vegetables, as well as nuts and chocolate, have high oxalate levels. Your liver also produces oxalate. Dietary factors, high doses of vitamin D, intestinal bypass surgery and several metabolic disorders can increase the concentration of calcium or oxalate in urine. Calcium stones may also occur in the form of calcium phosphate.
• Struvite stones. Struvite stones form in response to an infection, such as a urinary tract infection. These stones can grow quickly and become quite large, sometimes with few symptoms or little warning.
• Uric acid stones. Uric acid stones can form in people who do not drink enough fluids or who lose too much fluid, those who eat a high-protein diet, and those who have gout. Certain genetic factors also may increase your risk of uric acid stones.
• Cystine stones. These stones form in people with a hereditary disorder that causes the kidneys to excrete too much of certain amino acids (cystinuria).

Factors that increase your risk of developing kidney stones include:

• Family or personal history. If someone in your family has kidney stones, you're more likely to develop stones, too. And if you've already had one or more kidney stones, you're at increased risk of developing another.
• Dehydration. Not drinking enough water each day can increase your risk of kidney stones. People who live in warm climates and those who sweat a lot may be at higher risk than others.
• Certain diets. Eating a diet that's high in protein, sodium and sugar may increase your risk of some types of kidney stones. This is especially true with a high-sodium diet. Too much sodium in your diet increases the amount of calcium your kidneys must filter and significantly increases your risk of kidney stones.
• Being obese. High body mass index (BMI), large waist size and weight gain have been linked to an increased risk of kidney stones.
• Digestive diseases and surgery. Gastric bypass surgery, inflammatory bowel disease or chronic diarrhoea can cause changes in the digestive process that affect your absorption of calcium and water, increasing the levels of stone-forming substances in your urine.
• Other medical conditions. Diseases and conditions that may increase your risk of kidney stones include renal tubular acidosis, cystinuria, hyperparathyroidism, certain medications and some urinary tract infections.

KIDNEY STONE SYMPTOMS

A kidney stone may not cause symptoms until it moves around within your kidney or passes into your ureter (the tube connecting the kidney and bladder). At that point, you may experience these signs and symptoms:

• Severe pain in the side and back, below the ribs
• Pain that spreads to the lower abdomen and groin
• Pain that comes in waves and fluctuates in intensity
• Pain on urination
• Pink, red or brown urine
• Cloudy or foul-smelling urine
• Nausea and vomiting
• Persistent need to urinate
• Urinating more often than usual
• Fever and chills if an infection is present
• Urinating small amounts of urine

KIDNEY STONE DIAGNOSIS

Kidney stones are usually diagnosed based upon your symptoms, a physical examination, and imaging studies (Computed tomography (CT) scan or ultrasound)

KIDNEY STONE TREATMENT

Treatment of a kidney stone that is causing obstruction depends upon the size and location of the stone, as well as your pain and ability to keep down fluids. If your stone is likely to pass, your pain is tolerable, and you are able to eat and drink, then you can be treated at home.

If you have severe pain or nausea, you will need to be treated with stronger pain medications and IV fluids, which are often given in the hospital. In addition, patients with stones and who also have a fever should be treated in the hospital as soon as possible to avoid a life-threatening infection.

Stones larger than 9 or 10 millimeters rarely pass on their own and generally require a procedure to break up or remove the stone. Some smaller stones also do not pass. Several procedures are available.

Shock wave lithotripsy (SWL) is a reasonable treatment option in many patients who need help passing a stone. Lithotripsy is particularly good for stones 1 cm or less in the kidney and upper ureter. Lithotripsy is not effective for treating large or hard stones. You may require medication to make you sleepy and reduce pain during lithotripsy treatment, although this depends upon the type of lithotripsy equipment used.

Lithotripsy is performed by directing high-energy shock waves toward the stone. These sound waves pass through the skin and bodily tissues and release energy at the stone surface. This energy causes the stone to break into fragments that can be more easily passed in the urine.

Percutaneous nephrolithotomy (PNL) is used for extremely large or complex stones, or large stones resistant to shock wave lithotripsy, may require a minimally invasive surgical procedure to remove the stone. In this procedure, a small endoscopic instrument is passed through the skin (percutaneously) of the back into the kidney to remove the stone.

Ureteroscopy is a common endoscopic procedure that uses a thin scope, which is passed through the urethra and bladder, into the ureter and kidney. This endoscope allows the urologist to see the stone and remove it, or to break up the stone into smaller pieces that can pass more easily. Ureteroscopy is often used to remove stones blocking the ureter, and sometimes for small stones in the kidney.

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HIGH BLOOD PRESSURE (HYPERTENSION)

Hypertension is the medical term for high blood pressure, namely a blood pressure above 140 mmHg systolic (upper value) and/or above 90 mmHg diastolic (lower value). Untreated hypertension increases the strain on the heart and arteries, eventually causing organ damage. Hypertension increases the risk of heart failure, heart attack (myocardial infarction), kidney failure leading to dialysis, and stroke. Fortunately, treatments to lower blood pressure are usually easy to take and can help prevent health problems.

LIFESTYLE CHANGES

Making lifestyle changes is an important first step in the treatment of high blood pressure. In some patients, lowering sodium (< 6 grams or less of table salt) and alcohol intake, keeping weight in the ideal range, engaging in regular aerobic exercise, and stopping smoking can be sufficient to control high blood pressure. However, many patients also require one or more medications to lower the blood pressure.

HIGH BLOOD PRESSURE MEDICATIONS

There are various medications that are commonly used to treat high blood pressure.

Some people will respond well to one drug but not to another. Therefore, it may take time to determine. If a person has very high blood pressure (eg, 160/100 mmHg or higher), then combination therapy with two drugs at the same time rather than monotherapy with one drug may be the initial step in blood pressure treatment. In addition, some people who are first treated with one drug do not have an adequate response with good control of the blood pressure. If this happens, a second medication may be added. Other options include raising the dose of the first drug or substituting a different drug, since some people will respond to a different type of high blood pressure medication.

Adding a second drug, particularly as a single-pill combination, may be more effective than increasing the dose of the first drug and is associated with fewer side effects, many of which occur more frequently with higher doses.

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DIABETIC KIDNEY DISEASE

Diabetic kidney disease (diabetic nephropathy) is a complication that occurs in some people with diabetes. In this condition the filters of the kidneys, the glomeruli, become damaged. Because of this the kidneys 'leak' abnormal amounts of protein from the blood into the urine. The main protein that leaks out from the damaged kidneys is called albumin. In normal healthy kidneys only a tiny amount of albumin is found in the urine. A raised level of albumin in the urine is the typical first sign that the kidneys have become damaged by diabetes.

What are the causes of diabetic kidney disease?

The development of kidney disease in people with diabetes is associated with higher blood glucose levels over periods of years. the raised blood glucose level may cause some proteins in the kidney filters (glomeruli) to link together and trigger a localised scarring process. This scarring process in the glomeruli is called glomerulosclerosis. It usually takes several years for glomerulosclerosis to develop and it only happens in some people with diabetes. As the condition becomes worse, scarred tissue (glomerulosclerosis) gradually replaces healthy kidney tissue. As a result, the kidneys become less and less able to do their job of filtering the blood. This gradual 'failing' of the kidneys may gradually progress to what is known as end-stage kidney failure.

Diabetic kidney disease is influenced by hypertension (high blood pressure), and in patients with hypertension acceleration through the stages of diabetic nephropathy may be more rapid.

How common is diabetic kidney disease?

Although diabetic kidney disease is more common in people with type 1 diabetes, there are more people with type 2 diabetes and diabetic kidney disease. This is because type 2 diabetes is much more common than type 1 diabetes.

Diabetic kidney disease is actually the most common cause of kidney failure. Around one in five people needing dialysis has diabetic kidney disease. Most people with diabetes do not need dialysis.

For people with type 1 diabetes

Microalbuminuria or proteinuria is rarely present at the time when the diabetes is first diagnosed. By five years after the diagnosis of diabetes, about 14 in 100 people will have developed microalbuminuria. After 30 years, about 40 in 100 people will have developed microalbuminuria. Some people with microalbuminuria progress to proteinuria and kidney failure.

For people with type 2 diabetes

At the time the diabetes is first diagnosed, about 12 in 100 people have microalbuminuria and 2 in 100 have proteinuria. This is not because diabetic kidney disease happens straightaway in some cases but because many people with type 2 diabetes do not have their diabetes diagnosed for quite some time after the disease had begun. Of those people who do not have any kidney problem when their diabetes is diagnosed, albuminuria develops in about 15 in 100 people, and proteinuria in 5 in 100 people, within five years.

Diabetic kidney disease is much more common in Asian and black people with diabetes than in white people.

What are the symptoms of diabetic kidney disease?

You are unlikely to have symptoms with early diabetic kidney disease - for example, if you just have albuminuria. Symptoms tend to develop when the kidney disease progresses. The symptoms at first tend to be vague and nonspecific, such as feeling tired, having less energy than usual, and just not feeling well. With more severe kidney disease, symptoms that may develop include:

• Difficulty thinking clearly
• A poor appetite
• Weight loss
• Dry, itchy skin
• Muscle cramps
• Fluid retention which causes swollen feet and ankles
• Puffiness around the eyes
• Needing to pass urine more often than usual
• Being pale due to anaemia
• Feeling sick

What increases the risk of developing diabetic kidney disease?

All people with diabetes have a risk of developing diabetic kidney disease. However there are certain factors that increase the risk of developing this condition. These are:

• A poor control of your blood sugar (glucose) levels. (The greater your HbA1c level, the greater your risk.)
• The length of time you have had diabetes.
• The more overweight you become.
• Having high blood pressure. The higher your blood pressure, the greater your risk.
• If you are male.

Is it possible to prevent diabetic nephropathy?

The development of diabetic nephropathy may be delayed or prevented by maintaining good control of blood glucose levels and blood pressure.

Attending annual diabetes health checks is important as early identification of kidney damage can allow you and your healthcare team to take action to limit progression of kidney disease.

What are the possible complications?

End-stage kidney failure

In people with proteinuria end-stage kidney failure develops in approximately 8 in 100 people after 10 years. If this occurs, then you would need kidney dialysis or a kidney transplant.

Cardiovascular diseases

All people with diabetes have an increased risk of developing cardiovascular diseases, such as heart disease, stroke and peripheral vascular disease. If you have diabetes and diabetic kidney disease, then your risk of developing cardiovascular diseases is increased further. The worse the kidney disease, the further increased the risk.

High blood pressure

Kidney disease has a tendency to increase blood pressure. In addition, increased blood pressure has a tendency to make kidney disease worse. Treatment of high blood pressure is one of the main treatments of diabetic kidney disease.

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