Presence of persistent protein leakage in the urine after initial evaluation by your Nephrologist is an indication for kidney biopsy. It is a safe procedure performed with ultrasound guidance using local anaesthetic agent to numb the area around the point of needle insertion overlying the scanned kidney. Complications are extremely rare, commonest being bleeding post-procedure which can present in the form of discoloration of urine (hematuria, blood in urine) subsiding over few hours. You would be advised bed rest post biopsy for at least 12 hours while avoid lifting heavy objects.