What Is Glomerulonephritis?
Glomerulonephritis (pronounced: gluh-mare-you-low-neh-FRY-tis) is a problem with tiny filtering units in the kidneys called glomeruli. When someone has glomerulonephritis, the glomeruli become (swollen and irritated) and the kidneys stop working properly.
This can lead to problems like too much fluid in the body, which can cause swelling in places like the face, feet, ankles, or legs. Glomerulonephritis also can cause kidney failure and kidney disease, but that's rare.
Glomerulonephritis can be acute (meaning it comes on suddenly) or chronic (developing over several months to years). How it's treated depends on which type a person has.
The good news about glomerulonephritis is that most of the time it gets better on its own — and, if it doesn't, there's a lot that doctors can do to prevent further damage.
How the Kidneys Work
Kidneys are fist-sized organs in the back that are shaped like kidney beans. Our bodies can't use everything we eat or drink, so some of it ends up in our blood as waste, along with other waste products that our bodies make naturally. The kidneys filter blood and remove these waste products and excess fluid, which then leave the body as urine (pee).
The blood filtering happens in tiny structures called nephrons. Each kidney has about a million nephrons. Each nephron has a glomerulus (the singular of glomeruli). This ball of tiny blood vessels is where the process of removing waste products and fluids from the blood begins. If the glomeruli aren't doing their job properly, it can lead to health problems.
Things that might cause acute glomerulonephritis include:
- an infection with group A streptococci bacteria (the bacteria that cause strep throat)
- a problem with the body's immune system or diseases that affect the immune system (like systemic lupus erythematosus and HIV)
- conditions that affect the blood vessels (like vasculitis and Henoch-Schönlein purpura)
While acute glomerulonephritis has known causes, sometimes doctors don't know why people get chronic glomerulonephritis.
Signs and Symptoms
Early signs of glomerulonephritis include:
- blood in the urine (red or brown pee)
- urine that might look foamy in the toilet (from too much protein)
- swelling around the face, eyes, ankles, legs, and abdomen — especially in the morning
- high blood pressure (hypertension)
With acute glomerulonephritis, these symptoms might come on suddenly, possibly after a skin infection or a case of strep throat. Chronic glomerulonephritis can take several months to years to develop, and a person might not notice it right away (unless a doctor tests for it).
If glomerulonephritis isn't caught early and treated, there's a chance of kidney damage or failure. Symptoms of kidney failure are:
- peeing more frequently
- reduced amounts of pee
- lack of appetite
- nausea and vomiting
- weight loss
- muscle cramps at night
- fatigue (tiredness)
- pale skin
- high blood pressure
- fluid buildup in the tissues
Someone who has these symptoms might not have kidney failure — many other things can cause them. But if you notice any of these problems, see a doctor right away to find out what's going on.
What Doctors Do
If you notice swelling, blood in your urine, or any other symptoms of glomerulonephritis, talk to a parent and make an appointment to see a doctor. The doctor will ask you about your symptoms and will probably want to get urine and blood samples.
Sometimes doctors do imaging scans, like an , to get a better look at the kidney. In some cases, the doctor will do a kidney while the patient is asleep to take a tiny sample of kidney tissue. The tissue is sent to a lab for testing, and the results may show why there's inflammation in the kidney. These kinds of tests help doctors figure out what's going on, what type of kidney damage is there, and what treatments might help.
Sometimes, acute glomerulonephritis gets better on its own. When treatment is needed, it's best to start as soon as possible. That way there's less chance of damage to the kidneys.
How doctors treat acute glomerulonephritis in teens depends on what's causing it, what tests (like a kidney biopsy) show, how severe any kidney damage is (based on the biopsy results), and what symptoms the patient has.
Things doctors might prescribe include:
- fluid restriction (limiting the amount of fluid someone drinks per day)
- a diet that's low in protein, salt, and potassium
- diuretics (medicines that make people pee more)
- medicines to lower blood pressure (if high blood pressure is a problem)
- antibiotics (if a bacterial infection is causing glomerulonephritis)
- steroids and other medicines that suppress the immune system (if an immune system problem is causing glomerulonephritis)
In most cases of acute glomerulonephritis, the damage to the glomeruli will eventually heal. How long this takes depends on what caused the condition, how long it lasted, and when treatment began.
Most teens with glomerulonephritis can live normal lives and take part in the same activities as everyone else. It's very rare that people with acute glomerulonephritis will not respond to treatment.
When someone doesn't respond to treatment, glomerulonephritis can become chronic.
Chronic glomerulonephritis means one of two things:
- Someone has had glomerulonephritis for many months or even years — the person may not have had any signs of a problem until the kidney was so injured that damage couldn't be reversed.
- Acute glomerulonephritis has become chronic because it didn't respond to treatment.
There's no specific way to treat chronic glomerulonephritis, so a doctor may recommend lifestyle changes to minimize further damage or slow down progression of the kidney disease.
If you have chronic glomerulonephritis, your doctor may recommend that you:
- limit the amount of protein, potassium, phosphorus, and salt you eat
- reduce the amount of fluids you drink
- take calcium supplements
- eat healthy foods and get plenty of exercise
- take certain medicines
If glomerulonephritis continues to damage the kidneys, they can eventually stop working. When that happens, a person may need to get kidney dialysis (a procedure that cleans the blood and removes fluids from the body) or a kidney transplant.
But most teens with glomerulonephritis don't need these procedures, and can continue to take part in sports or other activities and live life just like other teens.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
© 1995- KidsHealth® All rights reserved.
Images provided by iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com