The amount of leftover (residual) urine can be measured by draining the bladder with a thin flexible tube (catheter) or by using ultrasound. The catheter method has a slight risk of causing infection or injury to the tube leading from the bladder (urethra). But the catheter method is safe when done carefully. And it may be less expensive than ultrasound.
ByHealthwise Staff Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine Anne C. Poinier, MD - Internal Medicine Adam Husney, MD - Family Medicine Specialist Medical ReviewerJ. Curtis Nickel, MD, FRCSC - Urology