In addition to a medical history and physical exam, other tests to diagnose nephrotic syndrome include:

• A 24-hour urine collection, which measures the total amount of protein in the urine collected over 24 hours. You will be diagnosed with nephrotic syndrome if you have more than 3500 mg of protein in your urine.
• Urine test for albumin. Lower levels of albumin in the blood can cause fluid to collect in the ankles, lungs, or abdomen.
• Creatinine and creatinine clearance. Results of these tests give information on how well your kidneys are working.
• Blood profile tests to measure the amount of protein, cholesterol, and sugar (glucose) in the blood.
• Kidney ultrasound to look at the kidneys. This exam can rule out other causes of your symptoms.

You may need other tests before treatment for nephrotic syndrome begins, including:

• A test for varicella (chickenpox) antibodies.
• A bone density scan.

In adults, additional testing usually includes:

• Serum protein electrophoresis (SPEP).
• Antinuclear antibodies (ANA).
• Antibody tests for systemic lupus erythematosus.
• C3 and C4 complement, proteins normally found in the blood.
• Tests for hepatitis B and hepatitis C.

Unless nephrotic syndrome is clearly caused by diabetes, a kidney biopsy is usually done to find the cause. Children do not usually have a biopsy.