A small sample of renal tissue is removed by a renal (kidney) biopsy to determine the reason(s) for renal failure, find out the cause of proteinuria, and evaluate the severity of the disease in diseases of the urinary system such as lupus nephritis.
Several ultrasound-guided renal biopsies might need a local or general anesthetic, depending on the age, but children need general anesthesia. Bedside renal biopsies are usually performed in the sick patients in the ICU and on the battlefield.

The patient must be hospitalized for an extended period in order to ensure the experience is successful. He will need to be completely bed-ridden for the day after the procedure. The next day, he can recover his typical activities.
Blood in the urine can be caused by coagulation measurements, so these need to be checked prior to renal biopsy. Occasionally complications such as bleeding from the biopsy site can occur. In the event of significant bleeding, additional procedures may be necessary to stop it.