Common causes/problems affecting the kidneys

This list is not exhaustive.

• Cancer of the kidney
• Infective
• Inflammatory
• Inherited
• Kidney stone disease
• Poisons/ Drugs
• Reflux nephropathy
• Obstructive Nephropathy
• Systemic
• Vascular

Renal Carcinoma

Renal Cell Carcinoma is the most common type in adults (3 per 10.000 people).

Click here for Malignancy guidance

Infective

Pyelonephritis:

Pyelonephritis is an infection of one or both kidneys, which may often start in the bladder and travel up the ureters to the kidneys. It does not normally occur in healthy conditions, and occurs when resistance is low, but is more likely to occur

• when the flow of urine from the kidneys is obstructed
• if the immune system is depressed
• when there is reflux of urine from the bladder back into the ureters
• and in diabetes where there is increased susceptibility to infection

The infection can be carried into the kidneys from another source in the body, through the bloodstream. It rarely affects men. Treatment is by antibiotics, either by mouth or by injection or intravenous route. It can be acute or chronic, rarely chronic pyelonephritis can lead to severe kidney damage and kidney failure.

Tuberculosis (TB)

Tuberculosis of the kidney is extremely rare.

Inflammatory

Glomerulonephritis is an inflammatory kidney response and it involves the glomeruli of the kidneys. It is a term for inflammatory diseases of the kidneys and can be triggered by infection. It arises as a result of immune complexes (antigen/ antibodycombination), antibodies, or immunoglobulin formed or deposited in the glomeruli, which causes an inflammatory response.

It may present mainly as:

• Nephritic Syndrome
• Nephrotic Syndrome
• Chronic Kidney Disease and Renal Failure

Click here for more information about Inflammatory Diseases of the Kidneys.

Inherited

Polycystic Kidney disease (Cysts of the Kidney):

Adult polycystic kidney disease is an inherited condition. Many cysts develop in both kidneys, destroying normal tissue and causing a gradual decline in kidney function, leading to end-stage renal disease. More than half the people who have this condition develop kidney failure at some time in their life, and therefore require dialysis or kidney transplant.

Kidney Stone Disease (Renal Calculi)

Stones form anywhere in the urinary tract, and symptoms vary with the site of the stone. Stones in the kidney itself are known as renal calculi and may cause pain in the back. The stones can be quite large – a stone may fill the pelvis of the ureter in the kidney; this is known as a Staghorn Calculus. However, they may also be very small and the stones may cause pain that varies from little or no pain, to excruciating pain.

Pain relief may be necessary (non-steroidal anti-inflammatory medication or pethidine). Blood may be present in the urine (haematuria).

Stones may cause obstruction of the urinary tract, and this can lead to infection and even a distension of the pelvis of the kidney and the kidney itself, this is known as hydronephrosis.

Small stones that are not causing complications only require help to be passed spontaneously, by drinking a lot of water. Alternatively, stones may be removed by ultrasound waves or by surgical means.

Click here for Image of Kidney Stone

Poisons/ Drugs

This causes inflammation of the kidney tubules and internal structures of the kidneys.

Acute tubulointerstitial allergic nephritis:

This is the result of a hypersensitivity reaction to drugs such as penicillin, methicillin, ampicillin, sulphonamides, non-steroidal anti- inflammatories (NSAID’s), frusemide and thiazide diuretics. This can cause acute renal failure, but the prognosis is usually good with treatment. High doses of steroids may be used.

Chronic tubulointerstitial nephritis - Analgesic Nephropathy:

This is caused by long – term excessive use of medications, such as over-the-counter painkillers, especially those containing phenacetin. Other medications involved are NSAID’s and aspirin. The kidneys lose their ability to concentrate urine with resultant polyuria (frequent urination) and proteinuria (protein in the urine) and the papillae (nodules) of the kidneys may slough off (“papillary necrosis”). This may block the ureters and cause acute obstruction. Treatment is largely supportive, and other analgesics such as paracetamol should be used.

Reflux Nephropathy (Vesico-Ureteric Reflux)

The ureters drain urine from the kidneys into the bladder and in the healthy state, one- way valves shut off the ureters from the bladder during urination. However, in some patients the valve is not competent, and during urination, a spurt of urine travels backwards up the urethra, and then comes back into the bladder. A chronic situation will lead to dilatation of the ureter and scarring of the kidney. This is a situation which can lead to infection, and kidney damage, which could persist into adult life. If the situation is severe enough, it can be a cause of end- stage renal failure in childhood or adulthood. Infection must be rigorously controlled, following diagnosis.

Obstructive Nephropathy

Obstruction may be unilateral (affecting one kidney) or bilateral (affecting both kidneys). Bilateral obstruction will become obvious much more early than unilateral obstruction; and infection above the site of obstruction may be a complication. Unilateral obstruction may be caused by stones, tumours, or a mass in the abdomen or pelvis pressing on the structures on one side. Bilateral obstruction may be caused by stricture or damage to the urethra, enlargement of the prostate (benign prostatic hypertrophy), bladder tumours, bladder stones, clots, or malignancy of the bladder or in the pelvis around the bladder. Treatment depends on the cause. The kidneys may not work properly after the obstruction is relieved, and careful monitoring and treatment will be needed.

Systemic

Diabetic Nephropathy

Kidney failure leading to the need for dialysis and renal (kidney) transplantation is a regular complication of diabetes. Over a period of time, as a result of poor circulation, and elevated levels of blood sugar, the kidneys become damaged.

There are special urine tests to detect early kidney damage, and these tests look for the presence of small amounts of albumin (a protein) in the urine.

Microalbuminuria – demonstrates minute amounts of protein in the urine, (which occurs long before a urine testing stick (dipstix) would detect the presence of protein in the urine).

Proteinuria –the detection of the presence of protein in the urine by dipstix, normally would indicate that kidney disease is well established.

At the first sign of microalbuminuria, drugs called ACE inhibitors are given to delay the progression of damage, and energetic measures to control blood pressure (for the same reason) and blood sugar are undertaken.

Autoimmune Disease:

Damage to both kidneys is caused by the depositing of immune complexes (antigen/ antibody complexes) which damage the kidneys at glomerular level. This is known as glomerulonephritis.

High Blood Pressure (Hypertension):

High blood pressure can be both the cause and consequence of kidney disease. Untreated hypertension over a period of time affects the blood vessels of the kidney, causing proteinuria and a progressive decline in renal function. Therefore it is important that blood pressure is controlled.

Hypertension may be secondary to various kidney disorders such as polycystic kidney disease, glomerulonephritis, chronic pyelonephritis, renal artery stenosis, kidney tumours and injury to the kidney tissue. It is important to perform investigations to find out the cause of the hypertension.

Amyloid Disease:

Amyloidosis is a rare disease in which various organs may be affected by the deposition of a protein (amyloid). It may occur as a reactive process to chronic infection and inflammation, such as TB, rheumatoid arthritis or Crohn’s Disease. It can also accompany malignant disease such as lymphoma and myeloma. Amyloid is usually deposited in the spleen, liver and kidneys. It can rarely occur in a hereditary form and can occur as an effect of normal ageing, (where it is normally deposited in the heart, and in the brain of people with Alzheimer ’s disease).

There is no cure for amyloidosis, but if the underlying disease is treated, it may slow the progression of the disease.

Vascular Disease

The renal artery which supplies blood to the kidney may be blocked by thrombus or embolus, leading to infarction or death of tissue, depending on the area involved, with varying effects on kidney function.

Renal Artery Stenosis is caused by the overgrowth of fibromuscular tissue in the artery, or atherosclerois, especially in the elderly. It is associated with hypertension (high blood pressure), and in certain conditions, could precipitate renal failure.

Amended April 2008