But when the detrusor muscle is overactive, it contracts while the bladder is filling with urine. This results in the increased desire, frequency, and urge to urinate. Stress incontinence, the other main type of bladder control problem, which may occur in addition to overactive bladder, involves involuntary urine leakage due to poor urethral support while lifting, coughing, sneezing, or running. The urethra is the canal that carries off the urine from the bladder. Women who have given birth are especially prone to stress incontinence.
Mixed symptoms are a combination of stress incontinence and the symptoms of overactive bladder.
Many people who experience problems with both urgency and frequency will eventually experience an urge incontinent episode or wetting accident. Currently, there are few studies available concerning the onset of overactive bladder. Although it can develop at any stage of life, the majority of people who develop overactive bladder conditions are menopausal and post-menopausal women. For women, their first leakage experience may come after childbirth, when the intense stress and stretching involved in labor weaken pelvic muscles and decrease their contractile abilities. Common conditions that place stress on the detrusor muscle, such as constipation, obesity, chronic lung disease, or a persistent cough, can also cause urine leakage.