Glomerulonephritis is damage to the tiny filters inside your kidneys (the glomeruli).
It is often caused by your immune system attacking healthy body tissue.
In most cases glomerulonephritis does not cause any noticeable symptoms and is often diagnosed when blood or urine tests are carried out for another reason.
Having blood in your urine does not mean that you definitely have glomerulonephritis, but you should see your GP so the cause can be investigated.
Why does glomerulonephritis happen?
Commonly, glomerulonephritis is the result of a problem with the immune system, which causes it to attack healthy tissue in the kidneys. However, there are many cases where the exact cause is unknown.
Conditions that can cause problems with the immune system include vasculitis and a type of lupus called systemic lupus erythematosus.
Glomerulonephritis is sometimes short-lived (acute), but more often it lasts for a long time (chronic).
Read more about the causes of glomerulonephritis.
How is glomerulonephritis treated?
The recommended treatment will depend on the cause and severity of your condition. Mild cases may not need any treatment.
Treatment can be as simple as making changes to your diet, such as eating less salt to reduce the strain on your kidneys.
Medications to lower blood pressure, such as angiotensin converting enzyme (ACE) inhibitors, are commonly prescribed for glomerulonephritis because they help protect the kidneys.
If the condition is caused by a problem with your immune system, medications called immunosuppressants may be used.