Glomerulonephritis is a type of kidney disease linked to inflammation of the tiny blood vessels in the kidneys known as glomeruli. It can result from streptococcal infections, certain diseases, or even long-term use of certain drugs.

Glomerulonephritis is a type of kidney disease that can be acute, which means it starts suddenly, or chronic, which refers to a gradual onset. Either type can be fatal.

Kidney disease affects 6 million adults in the United States, or 2.4% of the population. This article discusses the causes, symptoms, risk factors, and treatments of glomerulonephritis.

The glomeruli act as tiny filters within the kidneys, each of which contains millions of glomeruli.

If the glomeruli become damaged, the kidney can no longer remove waste and excess fluids efficiently. This means the body cannot filter blood and protein, which it excretes in the urine.

Primary glomerulonephritis refers to the occurrence of glomerulonephritis without an accompanying condition. Secondary glomerulonephritis occurs due to another disease, such as diabetes, lupus, infection, or drug use.

Acute glomerulonephritis mostly affects children and young adults, ages 2 to 14 years old. It may appear suddenly, following a throat or skin infection.

Symptoms include:

  • puffiness of the face
  • urine that is frothy and dark
  • decreased urination
  • fatigue
  • fever
  • stomach pain
  • high blood pressure

Chronic glomerulonephritis develops over a long time, often without obvious symptoms. However, it can result in complete kidney failure.

Individuals with glomerulonephritis might experience:

  • blood or protein in the urine
  • high blood pressure
  • swollen ankles or face due to water retention
  • urinating frequently during the night
  • bubbles or foam in the urine, due to excess protein

A person with kidney failure may experience a lack of 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 also feel dry and itchy.

Some people with the condition undergo intense pain, stiffness, or fluid in the joints.

The glomerulus is a tiny, ball-shaped structure that 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, are tiny filters that remove waste from the blood — this waste becomes urine. Each glomerulus attaches to the opening of a tubule. Filtered blood returns to the bloodstream, while urine containing the impurities from the blood is excreted into 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, which damages the kidneys’ ability to filter blood properly. Waste collects in the bloodstream, and the kidneys can eventually fail without treatment.

The condition also causes a lack of protein in the blood because it is expelled from the body in urine instead of entering the bloodstream.

Scarring

Glomerulonephritis can lead to scarring of the glomeruli.

Certain conditions, including lupus and diabetes, may cause scarring of the glomeruli, also known as glomerulosclerosis, or sclerosis of the glomeruli.

Scars develop due to the inflammation. This can lead to protein in the urine and eventual kidney failure.

High blood pressure can damage the kidneys and prevent them from functioning properly. 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 across the world, including the United States.

Anyone with diabetes can develop nephropathy. Health experts believe high glucose levels increase blood flow into the kidneys, straining the filtering process and raising blood pressure. The capillaries in the glomerulus collapse and can leave the glomeruli scarred.

People with diabetes need to control their glucose intake by eating a balanced, nutritious diet and keeping their blood pressure below 140 over 90 millimeters of mercury (mm Hg), or 130/80 mm Hg for people at high risk. They can do this using methods such as ACE inhibitors to lower their blood pressure. 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 stand-alone disease, without a known cause. More than half of those with FSGS will develop kidney failure within 5 to 10 years.

The cause of glomerulonephritis is often unclear, but certain risk factors can affect the likelihood of the condition.

Post-streptococcal glomerulonephritis can result from streptococcal infections of the throat or, in rarer cases, impetigo, a skin infection. However, 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 generally do not have a family member who also has the condition.

Long-term use of certain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or aspirin, can increase the risk.

People with Hodgkin’s lymphoma, sickle cell disease, and systemic diseases, especially diabetes, are at higher risk.

As many people have no symptoms, it may take a routine checkup or tests linked to hypertension or fatigue to reveal glomerulonephritis. However, diagnosis can be difficult, as the causes are often unknown.

Tests include a urine test to detect blood or protein in the urine and testing for antigens and antibodies in the blood.

Kidney function tests involve examining blood and urine samples to determine the levels of certain substances that the kidneys release, such as sodium, chloride, potassium, and urea. These tests can also tell 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.

If there is evidence of damage, imaging tests may follow, including possible X-rays, ultrasounds, or CT scans.

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 a doctor may prescribe antibiotics to kill the pathogens causing the infection.

The individual will likely 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. Additionally, corticosteroids and immunosuppressing drugs can help control inflammation.

Temporary dialysis may be necessary in cases of acute glomerulonephritis. In dialysis, a machine does the kidneys’ job of filtering out waste products from the body while also helping control hypertension and 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 has no other health issues. For people who cannot receive a transplant, dialysis may be the only option.

Glomerulonephritis can lead to hypertension, heart failure, pulmonary edema, and damage to other organs.

Without treatment, the kidneys might fail completely. Waste products build up quickly, making emergency dialysis necessary.

When the kidney function drops to less than 15% of its typical capacity, doctors will diagnose the individual with end stage kidney disease. These people will require regular dialysis or a kidney transplant to stay alive.

Most forms of glomerulonephritis are not preventable, 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 sex using a barrier method, such as a condom.
  • Avoid illegal intravenous (injection via the veins) drug use and the 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.

Glomerulonephritis occurs when the glomeruli in the kidney are damaged. This prevents the kidneys from properly filtering waste and excess fluid. Depending on the symptoms, glomerulonephritis can be acute or chronic.

Streptococcal infections or other infectious diseases, such as tuberculosis (TB) and syphilis, can also be the cause. A doctor can run tests to diagnose you with glomerulonephritis. Once they determine the cause and how serious the condition is, a doctor can suggest treatment.

People can help prevent glomerulonephritis by maintaining their health, such as consulting a doctor if they have a strep infection with a sore throat and managing diabetes or blood pressure.