A kidney biopsy (renal biopsy) is a procedure where a small piece of kidney tissue is removed and examined under a microscope. It is the gold standard for diagnosing kidney diseases, determining the cause of unexplained kidney failure, and guiding treatment decisions. While blood and urine tests provide important information, a biopsy gives definitive answers about what is happening inside your kidneys.
Why is a Kidney Biopsy Done?
- Unexplained kidney failure — when blood tests alone cannot determine the cause
- Nephrotic syndrome — heavy proteinuria (protein in urine) to identify the specific type
- Glomerulonephritis — to diagnose and classify inflammation of kidney filters
- Kidney transplant evaluation — to assess for rejection or recurrence of disease
- Unexplained hematuria — blood in urine with no clear cause
- Systemic diseases affecting the kidney — lupus nephritis, vasculitis, amyloidosis
- To determine the degree of kidney scarring and fibrosis
- To guide treatment decisions — some conditions require specific immunosuppressive therapy
Types of Kidney Biopsy
Percutaneous (Needle) Biopsy
The most common type. A thin needle is inserted through the skin into the kidney under ultrasound or CT guidance. It is minimally invasive, done under local anaesthesia, and takes only 15-20 minutes. Most patients go home the same day.
Open / Surgical Biopsy
A small incision is made and a piece of kidney is surgically removed. Reserved for patients who cannot have a percutaneous biopsy (bleeding disorders, solitary kidney, failed percutaneous attempt). Done under general anaesthesia.
The Procedure
Preparation
You lie face down (prone position). Blood tests are done to check clotting (PT/INR, platelets). Blood pressure is controlled. The biopsy area is cleaned and local anaesthesia is given.
Guidance
Ultrasound is used in real-time to visualise the kidney and guide the needle. The doctor identifies the lower pole of the kidney — the safest area for sampling.
Biopsy
A spring-loaded biopsy needle is inserted through a small nick in the skin. You may feel a brief pressure sensation. 2-3 passes are usually made to obtain adequate tissue. The whole process takes 15-20 minutes.
Recovery
You must lie flat for 4-6 hours after the biopsy to prevent bleeding. Blood pressure and pulse are monitored every 15 minutes for the first hour. Most patients go home the same evening.
Preparation Before Biopsy
- •Stop blood thinners (warfarin, aspirin, clopidogrel) as directed by Dr. Goel
- •Stop NSAIDs (ibuprofen, diclofenac) 5-7 days before
- •Inform about allergies, especially to local anaesthetics or contrast dye
- •May need to stop dialysis the day before to prevent bleeding
- •Light breakfast on the day of biopsy — no need to fast
- •Arrange someone to drive you home afterwards
Risks
Kidney biopsy is generally safe, but potential complications include:
- Bleeding — blood in urine (most common, usually self-limiting)
- Perinephric hematoma — collection of blood around the kidney
- Severe bleeding requiring transfusion or embolisation (rare, less than 1%)
- Pain at biopsy site — usually mild and manageable with painkillers
- Infection — very rare with proper sterile technique
- Pneumothorax (collapsed lung) — extremely rare with prone position
What Do the Results Mean?
The kidney tissue is examined by a nephropathologist. Results identify the specific disease (e.g., IgA nephropathy, membranous nephropathy, diabetic nephropathy, lupus nephritis), the degree of inflammation, scarring (fibrosis), and chronicity. This information is critical for choosing the right treatment — some conditions respond to immunosuppression while others require blood pressure control alone. Results typically take 5-7 working days.
Need a Kidney Biopsy?
Dr. Rajesh Goel performs kidney biopsies with expert ultrasound guidance and ensures a safe, comfortable experience. The results help guide precise, targeted treatment.