What is glomerulonephritis?
Glomerulonephritis is a disease that involves inflammation of the glomeruli — the filtering units of the kidneys. The glomeruli are found in the nephrons. This inflammation and subsequent damage to the glomeruli affects their ability to filter waste products and excess water from the blood.
Glomerulonephritis (also known as nephritis) may be either acute glomerulonephritis, with a sudden onset of inflammation, or chronic glomerulonephritis, involving persistent inflammation that comes on more gradually.
Symptoms of glomerulonephritis
Sometimes there are no symptoms of glomerulonephritis and the disease is picked up only incidentally by the detection of microscopic amounts of blood or protein on a routine urine test taken in your doctor’s surgery. About half of people with acute glomerulonephritis have no symptoms.
Sometimes the blood in the urine (haematuria) can be seen with the naked eye, making the urine pink or brown coloured. There may be less urine than normal. Blood in the urine is a symptom that should always be investigated.
Glomerulonephritis can be associated with fluid retention, which causes swelling and puffiness, particularly of the face, and maybe of the hands, legs and scrotum.
Foamy urine is another sign of glomerulonephritis. This is caused by the loss of protein (albumin) through the kidneys into the urine. Doctors call this proteinuria or albuminuria. Normally, protein shouldn’t leak out into the urine like this – it should stay in the bloodstream.
High blood pressure may develop as a serious complication of glomerulonephritis.
Chronic glomerulonephritis may remain silent for a long period with only mild symptoms, until kidney failure occurs. Symptoms of kidney failure include lack of appetite, nausea and vomiting, fatigue, difficulty sleeping, dry and itchy skin, and passing a smaller amount of urine than normal. Glomerulonephritis can be sudden and severe — progressing to kidney failure very rapidly — but this is rare.
Causes of glomerulonephritis
The most common cause of glomerulonephritis occurs when the body’s immune system attacks the glomeruli. These autoimmune types of acute glomerulonephritis include IgA nephropathy, where the antibody immunoglobulin A (IgA) builds up in the kidneys.
Young adults are the most likely people to be affected by IgA nephropathy. The first sign of disease is often an episode of passing blood-stained urine in association with an infection such as flu or a sore throat. The red urine episode usually occurs within a day or so of the respiratory infection and comes to an end by itself.
Systemic lupus erythematosus (SLE or lupus) is another autoimmune disease which may cause glomerulonephritis. This is sometimes referred to as lupus nephritis and may affect up to 60 per cent of people with lupus. Significant damage can occur to the kidneys before symptoms may occur, so it’s important to have regular urine tests.
Goodpasture syndrome is an uncommon autoimmune disease that attacks the lungs and kidneys.
In post-streptococcal glomerulonephritis, another type of glomerulonephritis, the blood-stained or dark urine episode does not occur until about 10 days after the sore throat. This delay coincides with the formation of antigen/antibody (immune) complexes that are deposited in the glomeruli and cause acute damage.
Children over the age of 5 years are the most likely group to be affected by post-streptococcal glomerulonephritis, particularly those living in indigenous communities.
Other bacteria, including staphylococci and pneumococci, can cause glomerulonephritis.
Causes of chronic glomerulonephritis
Chronic glomerulonephritis can develop over many years and in many people, the cause can’t be found. Sometimes it arises from acute glomerulonephritis that didn’t resolve. Other known causes include malaria and hepatitis.
Risk factors for glomerulonephritis
Some risk factors and conditions put a person at greater risk of getting glomerulonephritis. These include lupus, diabetes, high blood pressure, and viral infections such as HIV, hepatitis B and C.
Diagnosis of glomerulonephritis
Early diagnosis of glomerulonephritis can help a person get treatment faster and may have a significant effect on the outcome for them by reducing deterioration in kidney function.
Often glomerulonephritis is first discovered when a person gets abnormal results in a routine urine test performed for other reasons.
For example, a urine test, either done by dipstick or by collecting a urine sample, may detect that you have protein in your urine. This is known as proteinuria or albuminuria and may be an early sign of kidney disease. It may also detect blood cells in your urine (haematuria).
A blood test may show high levels of creatinine in the blood. Creatinine is a waste product normally excreted by the kidneys and passed out in the urine. If the kidneys are not working properly, levels of creatinine rise in the blood.
Your creatinine levels can be used to calculate your estimated glomerular filtration rate (eGFR) – a measure of how efficiently your kidneys are cleaning your blood.
While these tests are not specific for glomerulonephritis, they give a picture of how well your kidneys are functioning, and in addition to your medical history and other symptoms, may suggest to your doctor that you need further investigations for glomerulonephritis.
To find out the cause of the glomerulonephritis, your doctor may suggest further blood tests, for example to look for autoantibodies if they suspect an autoimmune cause.
Ultrasound, or a CT scan or MRI scan, may be used to look at your kidneys if your blood tests suggest there is a problem or damage to your kidneys.
Your doctor may also suggest a renal (kidney) biopsy to make the diagnosis (and determine the type) of glomerulonephritis. This involves taking a tiny piece or pieces of kidney tissue for microscopic examination. The biopsy is done under local anaesthetic, and you will have to rest in bed for at least 6 hours after the procedure.
Treatment of glomerulonephritis
Treatment depends largely on the type of glomerulonephritis you have, and the severity of the disease. Usually, the acute form eventually goes away by itself. If there is a treatment for the specific cause of the acute glomerulonephritis then this is recommended.
In children with glomerulonephritis following a streptococcus infection (post-streptococcal glomerulonephritis), antibiotics may be given to eradicate the infection if it is still present, and the nephritis usually resolves completely.
If glomerulonephritis is due to an autoimmune disease, oral corticosteroids may be needed to suppress the immune system. Similarly, if the glomerulonephritis is progressing rapidly, corticosteroids may be recommended.
In most cases, there is no specific cure available. A low-protein, low-salt diet may be advised to take the load off the kidneys. Similarly, restricting your fluid intake and taking diuretics may be required if swelling is a continuing problem.
In people with high blood pressure, medicine to control the blood pressure is one of the most important treatments. In chronic glomerulonephritis, taking one of the types of blood pressure medicines called an ACE inhibitor or Angiotensin-receptor blocker (ARB) will reduce blood pressure and reduce the excretion of protein in the urine. These medicines should slow the progression of chronic glomerulonephritis.
Self-care for glomerulonephritis
Your doctor will advise if there are things you can do to improve your condition. These may include:
- eating less protein, less salt and potassium
- taking blood pressure medicines as directed
- taking diuretics as directed to reduce swelling
- reducing your fluid intake
- taking calcium supplements
- getting regular exercise.
Kidney Health Australia has many useful resources for people living with kidney disease.
Many forms of glomerulonephritis can be avoided by living a healthy lifestyle. People with high blood pressure should manage their condition with a healthy diet, especially one low in salt, get plenty of exercise and take medication as needed.
People at high risk of kidney disease, such as those with high blood pressure, cardiovascular disease, or diabetes, and indigenous Australians, benefit from regular screening to identify kidney disease in its early stages.
A Kidney Health Check, which involves a urine test, blood test and blood pressure measurement, is recommended at regular intervals. This is important because kidney disease generally doesn’t have any symptoms until it is very advanced.
Others things you can do to avoid glomerulonephritis are:
- seek medical advice promptly if you think you may have a strep throat
- practice safe sex
- avoid illicit drug use.
Long-term outlook and complications of glomerulonephritis
The great majority of children with acute glomerulonephritis will recover in a period of weeks to months without complications. Adults tend to recover more slowly.
The outlook for chronic (ongoing) glomerulonephritis is more variable depending upon the type.
Glomerular disease is one of the most common causes of end-stage kidney disease in Australia. (Diabetes is the most common cause.) End-stage kidney disease is when your loss of kidney function reaches an advanced stage. Your kidneys cannot cope with filtering the waste and excess fluid from your blood on their own. Without dialysis or a kidney transplant, toxins will build up in the body and a person may only be able to survive a few weeks or months.
This is why it’s important to diagnose glomerulonephritis or any kidney disease early, so that you can be treated and follow self-help measures to slow the progression of kidney damage.
Glomerulonephritis can cause high blood pressure due to its effects on the kidneys.
What type of doctor looks after someone with glomerulonephritis?
Your General Practitioner is usually the first doctor you will have contact with regarding your glomerulonephritis, but you may be referred to a Nephrologist (renal medicine or kidney specialist).