Urinary incontinence, or leakage of urine, is a common gynecological complaint, especially as women age. There are several different types of urinary incontinence. Stress incontinence occurs when a woman experiences urine leakage when she coughs, sneezes, or during exercise. It is caused by a weakening of the bladder muscles or the muscles of the urethra, the tube which voids urine. Urge incontinence, or overactive bladder, occurs when the bladder muscles contract too often or there is a problem with the nerve impulses to the bladder. Mixed incontinence is a combination of both stress and urge incontinence. Overflow incontinence is a steady loss of urine due to a blockage in the urethra or an underactive bladder that does not completely void.