Patient Basics: Glomerulonephritis

Glomerulonephritis is inflammation of the glomeruli, the tiny filters in the kidneys that clean waste and extra fluid from the blood. When the filters are inflamed, blood and protein leak into the urine, and the kidneys can’t do their job as well. It can come on suddenly after an infection or build slowly over years. Because it can lead to kidney failure, early diagnosis and treatment matter.

Key points

• Warning signs include pink, brown or cola-colored urine, foamy urine, puffy eyes or swollen legs, and high blood pressure.
• Causes include strep and other infections, IgA nephropathy, lupus and inflammation of blood vessels (vasculitis).
• Urine and blood tests show the problem. A kidney biopsy often pins down the type.
• Treatment depends on the cause. It may include blood pressure medicines that protect the kidneys, medicines that calm the immune system and, for some people, dialysis.
• Children who get it after strep throat usually recover fully.

Glomerulonephritis symptoms

Some people have no symptoms, and the problem shows up only on a routine urine test. Others notice:

• Urine that looks pink, red, tea-colored or cola-colored, from blood
• Foamy or bubbly urine, from protein
• Swelling (edema) around the eyes, often worse in the morning, and in the hands, feet, ankles or belly
• High blood pressure, sometimes with headaches
• Peeing less than usual
• Tiredness, nausea, poor appetite or itchy skin as waste builds up in the blood
• Shortness of breath, if fluid collects in the lungs

The underlying cause can add its own symptoms, such as a rash, joint pain, fever, sinus problems or coughing up blood.

What causes glomerulonephritis

Infections

• After strep. Glomerulonephritis can follow strep throat by 1 to 3 weeks, or a strep skin infection (impetigo) by several weeks. It is most common in school-age children.
• Other infections, such as a heart valve infection (endocarditis), hepatitis B or C, or HIV.

Immune system diseases

• IgA nephropathy. This is the most common type worldwide. Visible blood in the urine often appears during or just after a cold or sore throat.
• IgA vasculitis (Henoch-Schönlein purpura). Mostly in children, it causes a raised purple rash on the legs and buttocks, joint pain and belly pain.
• Lupus, which can inflame the kidneys (lupus nephritis).
• ANCA vasculitis, including granulomatosis with polyangiitis (Wegener’s), which can also affect the lungs and sinuses.
• Anti-GBM disease (Goodpasture syndrome), in which antibodies attack the filters of the kidneys and sometimes the lungs.

Fast and slow forms

Rapidly progressive glomerulonephritis damages the kidneys over days to weeks and is a medical emergency. Chronic glomerulonephritis develops quietly over years and may be found only when kidney function is already low.

How it’s diagnosed

• Urine tests. A urinalysis looks for red blood cells, clumps of red cells shaped like the kidney’s tiny tubes (casts), and protein. A urine protein or albumin ratio measures how much protein is leaking.
• Blood tests. Creatinine and estimated glomerular filtration rate (eGFR) show how well the kidneys filter. Other tests check urea, salts and protein levels.
• Tests for the cause. These may include complement levels, lupus antibodies, ANCA and anti-GBM antibodies, a strep antibody test, and tests for hepatitis and HIV.
• Kidney ultrasound to check the size and shape of the kidneys.
• Kidney biopsy. A thin needle passed through the back, guided by ultrasound, takes a tiny sample. It often shows the exact type and how much scarring there is, which guides treatment.

How glomerulonephritis is treated

Protecting the kidneys

• Blood pressure medicines called ACE inhibitors (such as lisinopril) or ARBs (such as losartan) lower blood pressure and reduce protein leak.
• SGLT2 inhibitors, such as dapagliflozin and empagliflozin, can slow kidney damage in many people.
• Water pills (diuretics) ease swelling.
• A low-salt diet helps control swelling and blood pressure. Your care team may also adjust protein, potassium or fluids.
• Avoid anti-inflammatory pain pills such as ibuprofen and naproxen unless your kidney doctor says they’re OK.

Treating the cause

• Glomerulonephritis after strep usually heals on its own. Antibiotics treat any strep infection that is still present.
• Immune-related types are treated with steroids such as prednisone and other medicines that calm the immune system, such as cyclophosphamide, rituximab or mycophenolate. Newer targeted medicines are approved for IgA nephropathy and lupus nephritis.
• Plasma exchange, which filters harmful antibodies out of the blood, is used for anti-GBM disease and some severe cases of vasculitis.
• Infections such as hepatitis or endocarditis are treated directly.

If the kidneys fail

Dialysis takes over the kidneys’ cleaning work. A kidney transplant is another option for kidney failure that doesn’t improve.

Living with glomerulonephritis

• Keep regular checkups and urine and blood tests.
• Check your blood pressure at home and keep a log.
• Eat less salt, stay active, keep a healthy weight and don’t smoke.
• Stay up to date on vaccines, especially if you take medicines that weaken the immune system.
• Plan pregnancy with your kidney doctor, since some kidney medicines can harm a developing baby.

When to see a doctor

• Pink, red, brown or cola-colored urine
• Foamy urine that doesn’t go away
• Swelling of the face, eyelids, legs or ankles
• A child with dark urine or puffy eyes a few weeks after strep throat or a skin infection
• A blood test showing your eGFR has dropped quickly

Get emergency care if you are making very little or no urine, or have shortness of breath, chest pain, confusion, coughing up blood, or a severe headache with vision changes.

Common questions about glomerulonephritis

What color is urine with glomerulonephritis?

It is often pink, red, brown or the color of tea or cola, because of blood from the inflamed filters. Protein can make it look foamy. In many people the urine looks normal, and the blood and protein show up only on a lab test, which is why routine urine checks are useful.

How long does it take a child to recover from glomerulonephritis?

Most children with glomerulonephritis after strep feel better within 1 to 2 weeks, as swelling and blood pressure settle. Small amounts of blood can stay in the urine for months, even a year or more, without causing harm. Nearly all children recover full kidney function with follow-up care.

Can kidneys start working again after dialysis?

Sometimes. When glomerulonephritis comes on suddenly, the kidneys may recover enough within weeks or months for dialysis to stop. Recovery is less likely when the kidneys have been scarred over many years. Your kidney doctor will check your kidney function regularly to see whether dialysis is still needed.

Is a fast drop in eGFR serious?

It can be. A large drop in eGFR over weeks or a few months, such as 20 points, needs a prompt visit. It can come from dehydration or a medicine, but it can also be a sign of active kidney inflammation. Urine and blood tests help sort out the cause quickly.

Questions to ask your doctor

• What type of glomerulonephritis do I have, and what caused it?
• Do I need a kidney biopsy?
• How well are my kidneys working now?
• What are the side effects of my treatment?
• What blood pressure and diet goals should I aim for?

Learn more

• Glomerulonephritis (MedlinePlus, U.S. National Library of Medicine)
• Glomerular disease (National Institute of Diabetes and Digestive and Kidney Diseases)

This guide is general information and doesn’t replace advice from your own doctor. Last updated October 2026.