Glomerulonephritis

Glomerulonephritis is inflammation of tiny filters in your kidneys called glomeruli, which can damage your kidney’s ability to remove waste and fluid from your blood. Some people show no symptoms, while others may notice changes in their urine or swelling in their body.

Table of contents

• What is glomerulonephritis?
• How glomeruli help your kidneys
• Types of glomerulonephritis
• Signs and symptoms
• What causes glomerulonephritis
• Risk factors
• How is it diagnosed
• Treatment options
• Possible complications
• Outlook and prognosis

What is glomerulonephritis?

Glomerulonephritis is a type of kidney disease that involves damage to the glomeruli, which are tiny filtering units inside your kidneys.^[1] The term describes a group of kidney diseases characterized by immune-mediated damage to the basement membrane, mesangium, or capillary endothelium of the glomeruli, leading to hematuria (blood in urine), proteinuria (protein in urine), and azotemia (waste products in the blood).^[5]

If you have glomerulonephritis, your kidneys can have trouble removing waste and fluid from your body.^[2] Each adult kidney contains around 1 million nephrons, and the glomeruli are essential parts of these filtering units.^[5] When something damages them, they cannot do their job properly, which means your kidneys may not work as well.^[2]

Many mild cases of glomerulonephritis resolve with treatment. However, if the condition becomes severe, it can lead to kidney failure.^[2] Most forms of glomerulonephritis are considered progressive disorders, and without timely therapy, they can progress to chronic glomerulonephritis characterized by progressive glomerular damage and tubulointerstitial fibrosis leading to reduced kidney function.^[5]

• Kidneys
• Glomeruli
• Nephrons

How glomeruli help your kidneys

The kidneys remove waste and extra fluid from the blood through filtering units called nephrons. Each nephron contains a filter, called a glomerulus.^[1] Glomeruli are tiny filtering units made of capillaries (tiny blood vessels) in your kidneys. You have almost a million of them. Their job is to remove waste and extra fluid from your blood. It’s the first step in the process of making urine.^[2]

Each filter has tiny blood vessels called capillaries. When blood flows into a glomerulus, tiny bits, called molecules, of water, minerals and nutrients, and wastes pass through the capillary walls. Large molecules, such as proteins and red blood cells, do not. The part that’s filtered then passes into another part of the nephron called the tubule. The water, nutrients and minerals the body needs are sent back to the bloodstream. The extra water and waste become urine that flows to the bladder.^[1]

Types of glomerulonephritis

Glomerulonephritis can come on suddenly (acute) or gradually (chronic).^[1] When glomerulonephritis starts suddenly, it’s called acute glomerulonephritis. When it happens slowly and lasts a while, it’s called chronic glomerulonephritis. Some people can have an acute attack and then a chronic condition years later.^[2]

Acute forms of glomerulonephritis can result from either a primary renal cause or a secondary illness that causes kidney manifestations. For instance, acute post-streptococcal glomerulonephritis is a typical example of acute glomerulonephritis secondary to a streptococcal infection; similarly, Staphylococcus aureus infection can also lead to glomerulonephritis.^[5]

Signs and symptoms

People with glomerulonephritis often don’t experience any warning signs of the disease.^[2] You may notice no symptoms of chronic disease. Your first indication that something is wrong might come from the results of a routine urine test (urinalysis).^[1]

Signs and symptoms of glomerulonephritis may vary depending on whether you have the acute or chronic form and the cause.^[1] But symptoms can include:^[2]

• Blood in your urine, which may make it look brown, pink or red
• Urine that appears foamy or bubbly
• Swelling in your legs or face
• High blood pressure
• Urinating less often or more often than usual
• Shortness of breath
• Nausea
• Pain in your joints or abdomen
• Rash
• Jaundice
• Weight loss or loss of appetite

You should contact a healthcare provider if you have one or more of these symptoms. Many other health conditions can cause similar symptoms. Your healthcare provider can evaluate your symptoms and tell you if glomerulonephritis is a possible diagnosis.^[2]

What causes glomerulonephritis

Glomerulonephritis occurs on its own or as part of another disease, such as lupus or diabetes.^[1] The reason glomerulonephritis appears is often unknown.^[2] But causes may include:^[2]

• A complication of bacterial endocarditis, an infection in your heart valves
• A complication of infections like strep throat, HIV or hepatitis C
• Problems with your immune system attacking healthy parts of your body, such as with lupus
• Anti-GBM disease (formerly Goodpasture syndrome), a group of autoimmune diseases that affect your lungs and kidneys
• IgA nephropathy, a kidney disease caused by a buildup of abnormal IgA antibody (immunoglobulin A)
• Rare diseases that inflame blood vessels like granulomatosis with polyangiitis (formerly Wegener’s disease), microscopic polyangiitis, Henoch-Schönlein purpura, or eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome)
• Genetics, meaning it runs in your biological family (this is rare)
• Certain types of cancer (like multiple myeloma)

In children, a common cause of glomerulonephritis is from a streptococcal infection, such as strep throat or upper respiratory infection. Glomerulonephritis usually occurs more than one week after an infection. This is often referred to as acute post-streptococcal glomerulonephritis.^[13]

Risk factors

Not everyone with risk factors will develop glomerulonephritis. And, not everyone with the condition has a risk factor. But, the following are known risk factors:^[2]

• A personal or family history of kidney disease
• Taking certain medications
• Exposure to specific toxins
• Having certain viral infections (like strep) or bacterial infections (bacterial endocarditis)
• Having an autoimmune condition

How is it diagnosed

Glomerulonephritis may be identified with tests if you have an acute illness or during routine testing during a wellness visit or an appointment managing a chronic disease, such as diabetes.^[10] Tests to assess your kidney function and make a diagnosis of glomerulonephritis include:^[10]

Urine test. A urinalysis can reveal signs of poor kidney function, such as red blood cells and proteins that should not be in urine or white blood cells that are a sign of inflammation. There also may be a lack of the expected levels of waste products.^[10]

Blood tests. Analysis of blood samples can reveal higher than expected levels of waste products in the bloodstream, the presence of antibodies that may indicate an autoimmune disorder, bacterial or viral infection, or blood sugar levels indicating diabetes.^[10]

Imaging tests. If your doctor detects evidence of kidney disease, he or she may recommend imaging tests that may show an irregularity in the shape or size of the kidney. These tests may be an X-ray, an ultrasound exam or a CT scan.^[10]

Kidney biopsy. This procedure involves using a special needle to extract small pieces of kidney tissue to look at under a microscope. A biopsy is used to confirm a diagnosis and to assess the degree and nature of tissue damage.^[10]

Treatment options

Treatment of glomerulonephritis and your outcome depend on whether you have the acute or chronic form and the cause.^[10] Treatment depends on the type of glomerulonephritis you have.^[1] Sometimes, glomerulonephritis is mild and goes away without treatment. Other times it leads to kidney failure and other complications.^[2]

Dietary changes

In mild cases, a doctor or dietitian will give you relevant advice about diet. You may be advised to reduce the amount of salt, fat, protein and potassium in your diet and drink less fluid. This should help control your blood pressure and ensure the amount of fluid in your body is regulated.^[9] A dietitian can help you make an eating plan with the right amounts of salt (sodium), potassium, and protein. You may also need to limit how much fluid you drink each day.^[19]

Medications

If glomerulonephritis is caused by problems with your immune system, medicines called immunosuppressants may be recommended. These medicines suppress your immune system. Suppressing your immune system can be effective, but it also increases your risk of infections and can cause other side effects, such as thinning of the bones (osteoporosis).^[9]

Steroids. You may be put on a course of medicines containing steroids such as prednisolone. Steroids are used to reduce swelling and suppress your immune system. Once your kidneys have started to recover, your dose of steroids will usually be lowered.^[9]

Blood pressure medicines. Glomerulonephritis often leads to high blood pressure, which can cause further kidney damage and other health problems. You may need to take medicines that lower blood pressure and help reduce the amount of protein that leaks into your urine, such as either an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB). Often, people who have high blood pressure and kidney disease need to take several medicines to control their blood pressure.^[9]

Other medicines. If your condition is thought to be linked to a viral infection, it may be treated with antiviral medicine. Individual symptoms can sometimes be treated. For example, swelling caused by a build-up of fluid may be treated with a type of medicine called a diuretic.^[9]

Other treatments

Plasma exchange. Plasma is a fluid that is part of the blood. It contains proteins that can make your kidneys inflamed. Plasma exchange involves removing some of the plasma from your blood. During the procedure, you’re connected to a machine that gradually removes some of your blood. The plasma is separated from the blood cells and removed. A plasma substitute is then added to the blood before it’s put back into your body. Plasma exchange may be used in certain circumstances if your condition is severe.^[9]

Dialysis or transplant. If you have severe glomerulonephritis that cannot be improved with other treatments, you may require kidney dialysis (a treatment that takes over part of the kidney’s job and removes waste products from your body) or a kidney transplant (where a healthy kidney from a donor is surgically implanted to replace your own kidney).^[9]

Lifestyle measures

Smoking may make kidney disease caused by glomerulonephritis worse. It also increases the risk of complications like heart disease and stroke, which are more common in people with glomerulonephritis.^[9]

As glomerulonephritis can make you more vulnerable to infections, it’s a good idea to protect yourself by having a seasonal flu vaccine and a pneumonia vaccine (also called the pneumococcal vaccine).^[9]

Possible complications

Some people develop complications from glomerulonephritis.^[2] Severe or prolonged inflammation associated with glomerulonephritis can damage the kidneys.^[1] Without timely therapy, glomerulonephritis can progress to chronic kidney disease, which leads to the retention of uremic toxins with subsequent progression into chronic kidney disease and end-stage renal disease along with their associated cardiovascular diseases.^[5]

Outlook and prognosis

Many mild cases resolve with treatment. If the condition becomes severe, it can lead to kidney failure.^[2] This illness may get better with treatment. But it often leads to long-term (chronic) kidney disease.^[19]

You should have regular reviews to check your blood pressure, the levels of salt and potassium in your urine and how well your kidneys are working.^[9] On an outpatient basis, kidney function, blood pressure, swelling, serum albumin, and urine protein excretion rate should be monitored.^[12]