n order to understand why Stress Urinary Incontinence (SUI) occurs, a quick refresher course on the female urinary anatomy might be helpful. The bladder has two functions. The first is to store urine produced by the kidneys and the second is to contract and push the urine through the urethra. Controlling the flow of urine out of the bladder is the sphincter muscle. The nervous system detects when the bladder is ready to be emptied and tells the sphincter to relax, allowing you to pee. When there is any sort of abdominal stress on the pelvic organs—the bladder, vagina, uterus, and rectum—SUI can occur.
It is important to understand the difference between stress incontinence (SUI) and urge incontinence (UUI) as they are treated differently. While Urge incontinence (UUI) involves the sudden and unstoppable loss of urine, SUI is not accompanied by the sensation of a sudden urge to urinate. The underlying cause for SUI is different from that of UUI. SUI is caused by a weak sphincter muscle and/or pelvic floor. Some people have both SUI and UUI, known as mixed incontinence. This means that they leak when they cough, sneeze, or exert pressure on their abdominal muscles; but they also feel the urgent need to go to the toilet and may not make it in time.
Specifically, there are two types of SUI: urethral hypermobility and intrinsic sphincteric deficiency (ISD). In the case of urethral hypermobility, the urethra shifts positions due to an increase in abdominal pressure. On the other hand, ISD refers to the inability to effectively seal off the sphincter, the ring of muscles whose main job is to remain tightened, keeping urine in the bladder. While there is no specific test for ISD, it is now generally believed that many women with SUI have at least some degree of ISD. Measurements of pressures taken during testing aid doctors in making the diagnosis.
SUI is the most common occurring form of incontinence in women under the age of 60 and accounts for more than half the cases.
While pregnancy and childbirth heads the list for causes of SUI, there are other health factors that put you at risk. They include loss of pelvic muscle tone (often with aging), hysterectomy, nerve and muscle damage from birthing or surgical trauma, obesity, menopause, chronic coughing due to smoking and lung disease, anatomical predisposition, and repeated heavy lifting or high impact sports