IgA Nephropathy

Overview

IgA nephropathy is a kidney condition that occurs when a protein called immunoglobulin A, or IgA, builds up in the tiny filtering units of the kidneys. These filters, called glomeruli, help remove waste and extra fluid from the blood. When IgA deposits collect in the glomeruli, they can cause inflammation and affect how well the kidneys filter blood.

IgA nephropathy is sometimes called Berger disease. It can develop at any age, although it is often found in young adults. The condition may be mild and stable for many years, or it may gradually affect kidney function over time. Some people have no symptoms and only discover the condition during routine urine tests.

Because the course of IgA nephropathy can vary from person to person, regular follow-up with a kidney specialist, called a nephrologist, is important. Monitoring helps assess kidney function, urine findings and blood pressure, and supports timely treatment decisions.

Symptoms

IgA nephropathy does not always cause noticeable symptoms, especially in the early stages. When symptoms occur, they may come and go. Common signs can include:

• Blood in the urine, which may make the urine look tea-colored, cola-colored or reddish
• Microscopic blood in the urine, found only through laboratory testing
• Foamy urine, which may suggest protein in the urine
• Swelling in the feet, ankles, legs, hands or around the eyes
• High blood pressure
• Fatigue or reduced energy, especially if kidney function is affected
• Discomfort in the back or sides in some cases

Some people notice visible blood in the urine after an upper respiratory infection, such as a sore throat or cold. However, blood in the urine can have many causes, so medical evaluation is needed to understand the reason.

Causes and Risk Factors

The exact cause of IgA nephropathy is not fully understood. It involves an abnormal immune response in which IgA proteins form deposits in the kidneys. These deposits can trigger inflammation and, in some people, scarring of the kidney filters.

IgA is part of the immune system and normally helps protect the body, especially in areas such as the throat, airways and digestive tract. In IgA nephropathy, certain forms of IgA may be more likely to collect in the kidneys.

Factors that may be associated with a higher risk include:

• A family history of IgA nephropathy or some kidney diseases
• Male sex in some populations
• Young or middle adulthood, although it can occur at other ages
• Certain ethnic or geographic backgrounds, as the condition is more common in some regions
• A history of recurrent respiratory or throat infections, which may be linked with flare-ups in some people

Having one or more risk factors does not mean a person will develop IgA nephropathy. Likewise, the condition can occur in people without obvious risk factors.

Diagnosis

IgA nephropathy may be suspected when urine tests show blood or protein, especially if these findings are persistent. Diagnosis usually begins with a medical history, physical examination and assessment of blood pressure.

Common tests used in the evaluation may include:

• Urine tests to look for blood, protein and other abnormalities
• Blood tests to assess kidney function and general health
• Blood pressure measurement, because high blood pressure can affect kidney health
• Imaging tests, such as ultrasound, to assess kidney size and structure when needed
• Kidney biopsy in selected cases, where a small sample of kidney tissue is examined under a microscope

A kidney biopsy is the most specific way to confirm IgA deposits in the kidneys. Not every person with blood or protein in the urine needs a biopsy. The decision depends on the overall clinical picture, test results and the nephrologist’s assessment.

Treatment Options

Treatment for IgA nephropathy depends on the severity of kidney involvement, blood pressure, level of protein in the urine, kidney function and overall health. The main goals are to protect kidney function, reduce inflammation when appropriate and manage complications.

Management may include:

• Regular monitoring of kidney function, urine findings and blood pressure
• Blood pressure control, which is often a key part of kidney protection
• Measures to reduce protein in the urine when recommended by a physician
• Lifestyle guidance, such as reducing excess salt intake, maintaining a healthy weight and avoiding smoking
• Careful management of cholesterol, diabetes or other conditions that may affect kidney health
• Immune-focused treatment in selected cases, depending on disease activity and risk
• Advanced kidney care if kidney function becomes severely reduced

Some people need only observation and supportive care, while others may require more active treatment. Treatment plans should be individualized and reviewed regularly. Patients should not stop or start any medication or supplement without consulting their healthcare provider, as some substances can affect the kidneys.

When to See a Doctor

Medical evaluation is recommended if you notice blood in the urine, persistent foamy urine, swelling of the legs or face, high blood pressure, or unexplained fatigue. These symptoms do not always mean IgA nephropathy, but they can indicate a kidney or urinary tract problem that should be assessed.

People already diagnosed with IgA nephropathy should attend regular follow-up visits, even when they feel well. Kidney conditions can change silently, and routine testing helps detect changes early.

Seek urgent medical attention if there is a sudden decrease in urination, severe swelling, shortness of breath, very high blood pressure symptoms, or a sudden worsening of general condition. Prompt medical care can help evaluate the cause and guide appropriate treatment.