What is glomerulonephritis (GN)?
Glomerulonephritis is a group of diseases which result in injury to the glomerulus. This can either be through an attack by your own immune system (autoimmune), scarring or other damage. When the glomeruli are injured, they are not able to rid the body of waste materials and extra water.
What is the glomerulus?
The glomerulus is the part of the kidney that filters the blood, the first step in the process of making urine. It is made up of a cluster of tiny blood vessels (capillaries). The capillary walls are so thin that as blood rushes through them, extra water and waste materials pass through the walls into the urinary space. There are about one million of these filtering units in each kidney. The glomerulus should not allow large amounts of protein or blood to filter into the urine.
What are the two major categories of glomerulonephritis (GN)?
The two major categories of GN are nephrotic syndrome and nephritic syndrome. In nephrotic syndrome, the glomerulus is injured in a way that allows large amounts of protein to leak into the urine. This results in swelling, usually in the legs but can also be in the body, arms and face if severe. Protein levels in the blood also are low while the levels of lipids (fat) are high. The kidney’s ability to clean the extra water and waste materials out of the blood may also be decreased (kidney failure) but this is not always the case. In nephritic syndrome, the glomerulus is injured in such a way that allows red blood cells to leak into the urine. The urine may be red or dark brown (tea) colored from the blood products, but the blood may not be visible. Protein may also leak into the urine, but not as much as in nephrotic syndrome. Kidney function is often lower. In severe cases, kidney failure can develop. Urine may not be produced in such cases. This can lead to swelling and high blood pressure.
What causes glomerulonephritis (GN)?
There are many causes of GN. Common causes include HIV, hepatitis B or C, and lupus. The trigger for many cases is not known, but is thought to be related to something that causes the immune system to attack the kidneys. A few cases of GN tend to run in families and have a genetic cause.
What are the symptoms of acute and chronic glomerulonephritis (GN)?
People who have nephritic syndrome might have symptoms that include:
- Blood in the urine, causing it to turn brown
- Less frequent urination
- Shortness of breath
- High blood pressure (in some cases)
- Fatigue, nausea
- Rashes, joint pain or abdominal pain can be seen in some cases
Patients with nephrotic syndrome may have the following symptoms:
- Urine that is foamy (this can be seen in people without nephrotic syndrome as well)
- Ankle, leg or facial swelling
- High blood pressure
- Frequent urination during the night
Some milder or less aggressive forms of both nephrotic and nephritic syndromes may only be found through blood or urine lab testing.