Kidney Biopsy: Why It Is Done and What to Expect

A kidney biopsy is a procedure in which a tiny sample of kidney tissue is taken with a thin needle and examined under a microscope. It can give an exact diagnosis when blood and urine tests alone are not enough, helping guide the right treatment. Dr. Satarupa Deb, Consultant Nephrologist at Bombay Hospital, South Mumbai, advises on when a biopsy is needed and explains each step clearly.

Why a Kidney Biopsy May Be Recommended

Many kidney diseases look similar on routine tests but need very different treatments. A biopsy may help identify the specific condition, show how active or advanced it is, and indicate how likely it is to respond to treatment.

• Significant protein in the urine or nephrotic syndrome
• Blood in the urine along with protein or declining kidney function
• Unexplained or rapidly worsening kidney function
• Suspected glomerulonephritis or kidney involvement in conditions such as lupus
• Evaluating a transplanted kidney that is not working as expected

Preparing for the Biopsy

A kidney biopsy is usually planned in advance, with a short hospital stay for observation. Before the procedure, your doctor will review your health and medicines and arrange a few tests.

• Blood tests including blood counts, clotting profile and kidney function
• An ultrasound of the kidneys to check their size and position
• Blood pressure should be well controlled before the procedure
• Blood thinners such as aspirin, clopidogrel or anticoagulants may need to be stopped for some days; never stop them without your doctor's advice
• You may be asked not to eat for a few hours beforehand

What Happens During the Procedure

For a native kidney biopsy, you will usually lie on your stomach; for a transplant kidney biopsy, you lie on your back. The skin is cleaned and numbed with local anaesthetic. Using ultrasound guidance, a thin biopsy needle is passed into the kidney and a small core of tissue is taken. You may be asked to hold your breath briefly while the sample is collected. Often two or more samples are needed.

The procedure itself generally takes a short time. Most people feel pressure or a brief clicking sensation from the biopsy device rather than significant pain.

Recovery and Possible Risks

After the biopsy, you will be asked to rest in bed for several hours while nurses monitor your blood pressure, pulse and urine. It is common to see a little blood in the urine for a short time. Most people can return to normal light activities within a day or two, but heavy lifting and strenuous exercise are usually avoided for about one to two weeks.

A kidney biopsy is generally considered safe, but as with any procedure there are risks. The most important is bleeding, which is usually minor and settles on its own. Rarely, bleeding may need a blood transfusion or a further procedure. Contact your doctor urgently if you notice heavy blood or clots in the urine, severe pain, dizziness or fever after going home.

Getting Your Results

The tissue is examined using light microscopy and, depending on the case, special stains, immunofluorescence and electron microscopy. Results may take several days to a couple of weeks for complete reporting. Dr. Satarupa Deb (MD Medicine, DM Nephrology, KEM Hospital, Mumbai) will explain the findings and discuss a treatment plan tailored to your diagnosis.

This page is for general information only and is not a substitute for a medical consultation. Please consult a qualified doctor for diagnosis and treatment.