Glomerulonephritis refers to a range of inflammatory kidney conditions of the tiny blood vessels in the kidneys, known as glomeruli.
It can be acute, which means it starts suddenly, or chronic, during which the onset is gradual. Either type can be fatal.
Kidney disease affects 4.9 million people in the United States, or 1.9 percent of the population.
The glomeruli act as tiny filters within the kidneys. Each kidney contains millions of glomeruli.
If the glomeruli become damaged, the kidney can no longer remove waste and excess fluids efficiently. Blood and protein cannot be filtered and are excreted in the urine.
Primary glomerulonephritis refers to the occurrence of glomerulonephritis without an accompanying condition, while secondary glomerulonephritis is caused by another disease, such as diabetes, lupus, infection, or drug use.
Acute glomerulonephritis may appear suddenly, following a throat or skin infection.
- puffiness of the face on waking up
- urine that is brown or contains traces of blood
- decreased urination
- fluid in the lungs leading to coughing and shortness of breath
- high blood pressure
Chronic glomerulonephritis develops over a long time, often without obvious symptoms. However, complete kidney failure can result.
Individuals with glomerulonephritis might experience:
- blood or protein in the urine
- high blood pressure
- swollen ankles or face, because of water retention
- urinating frequently during the night
- bubbles or foam in the urine, caused by excess protein
A person with kidney failure may experience poor appetite, nausea, and vomiting. They may feel tired due to disruptions to their sleeping pattern, with muscle cramps occurring during the night. The skin might feel dry and itchy.
Some people with the condition undergo intense pain in the upper back, behind the ribs, as a result of kidney pain.
A healthy adult urinates around 2 to 3 pints daily. People with severe glomerulonephritis may not urinate for 2 or 3 days.
The glomerulus is a tiny, ball-shaped structure, and it is part of the nephron. A nephron consists of one glomerulus and a small fluid-collecting tube, or tubule. Both are key structures in the kidney.
Capillary blood vessels, or glomeruli, make up the glomeruli. These are tiny filters that remove waste from the blood. The waste becomes urine.
Each glomerulus attaches to the opening of a tubule.
Filtered blood returns to the bloodstream. Urine containing the impurities from the blood is excreted to the bladder.
The tubules retain important substances, such as protein.
The urine passes from the kidney to the bladder through a tube called the ureter and then leaves the body through urination.
When these filters become inflamed, the individual has glomerulonephritis.
The damage caused by glomerulonephritis reduces the ability of the kidneys to filter blood properly. Waste collects in the bloodstream, and the kidneys might eventually fail.
The condition also causes a lack of protein in the blood, because it gets expelled from the body in urine, instead of entering the bloodstream.
The cause is often unclear, but there are risk factors that can affect the likelihood of glomerulonephritis.
Post-streptococcal glomerulonephritis can result from streptococcal infections of the throat or, in rarer cases, impetigo, a skin infection. Improved treatments for most streptococcal infections mean that this is now less common.
Infectious diseases, such as tuberculosis (TB) and syphilis, can lead to glomerulonephritis. This is also true of bacterial endocarditis, an infection of the heart valves. Viral infections, such as HIV, hepatitis B, and hepatitis C also increase the risk.
Acute glomerulonephritis may develop into chronic, or long-term, glomerulonephritis.
Genetic factors can play a role, but people with glomerulonephritis do not normally have a family member who also has the condition.
People with Hodgkin’s, sickle cell disease, and systemic diseases, especially diabetes are at higher risk.
Scarring of the glomeruli can also lead to glomerulonephritis.
Conditions including lupus and diabetes may cause scarring of the glomeruli, also known as glomerulosclerosis, or sclerosis of the glomeruli.
Scarring occurs when growth factors activate the glomerular cells to produce scar material.
The growth factors may be produced by the glomerular cells or carried by circulating blood. This can lead to protein in the urine and eventual kidney failure.
High blood pressure can damage the kidneys and prevent normal function. At the same time, the kidneys play an important part in regulating blood pressure. Glomerulonephritis can cause hypertension because of the damage to kidney function.
Diabetic nephropathy is the main cause of kidney failure in the U.S.
Anyone with diabetes can develop nephropathy. High glucose levels are thought to make the blood flow into the kidney at a higher speed, putting a strain on the filtering process and raising blood pressure. The capillaries in the glomerulus collapse and can leave the glomeruli with scarring.
People with diabetes should control their glucose intake by eating a balanced, nutritious diet, and keep their blood pressure below 140 over 90 millimeters of mercury (mmHg), for example, by using medications, such as ACE inhibitors. This can help prevent kidney complications, such as glomerulonephritis.
Focal segmental glomerulosclerosis (FSGS) refers to scarring in scattered regions of the kidney, either due to a systemic disorder or as a standalone disease, without a known cause. It normally progresses to kidney failure over 5 to 20 years, earlier in some cases.
As many people have no symptoms, it may take a routine check-up or tests linked to hypertension or fatigue to reveal glomerulonephritis. Diagnosis can be difficult, as the causes are often unknown.
Tests include a urine test to detect blood or protein in the urine, testing for antigens and antibodies in the blood.
Kidney function tests involve examining blood and urine samples that show the levels of certain substances released by the kidneys, such as sodium, chloride, potassium, and urea, as well as whether the person is producing less urine than usual.
A kidney biopsy involves using a small needle to take a sample of kidney tissue. This will show how serious the condition is.
Treatment depends on whether the condition is acute or chronic, the underlying cause, and the severity of symptoms.
Glomerulonephritis after a strep infection usually clears up without treatment, but the doctor may prescribe antibiotics to kill the pathogens causing the infection.
The individual will probably have to reduce fluid intake and avoid drinks or food containing alcohol or high levels of protein, salt, or potassium.
Diuretics can help reduce hypertension and the slow decline of kidney function, and blood pressure medication relaxes the blood vessels. Corticosteroids and immune-suppressing drugs control inflammation.
Temporary dialysis may be necessary in cases of acute glomerulonephritis. In dialysis, a machine does the kidney’s job of filtering out waste products from the body. Dialysis also helps to control hypertension and to remove surplus fluid.
A person with autoimmune problems may undergo plasmapheresis, a mechanical process that removes plasma with antibodies from the blood, and replaces it with other fluid or donated plasma.
A kidney transplant may be possible if the individual is otherwise healthy. For people who cannot receive a transplant, dialysis may be the only option.
Without treatment, the kidneys might fail completely. Waste products build up quickly, making emergency dialysis necessary.
When the kidney function drops to less than 10 percent of its normal capacity, the individual is diagnosed with end-stage kidney disease and will require regular dialysis or a kidney transplant to stay alive.
Most forms of glomerulonephritis cannot be prevented, but there are some ways to reduce the risk:
- Seek medical attention for a strep infection that causes a sore throat or impetigo.
- Keep diabetes and blood pressure under control.
- Practice safe sex using condoms.
- Avoid illegal intravenous drug use and sharing of needles.
Choosing a healthy lifestyle with plenty of exercise, quality sleep, and a well-rounded diet can reduce the risk of glomerulonephritis as well as the risk of other infections and hypertension.