Urinary incontinence is the involuntary excretion of urine from one's body. Stress incontinence is essentially due to pelvic floor muscle weakness. It is loss of small amounts of urine with coughing, laughing, sneezing, exercising or other movements that increase intrabdominal pressure and thus increase pressure on the bladder. Physical changes resulting from pregnancy, childbirth, and menopause often cause stress incontinence, and in men it is a common problem following a prostatectomy. It is the most common form of incontinence in women and is treatable. Urge incontinence is involuntary loss of urine occurring for no apparent reason while suddenly feeling the need or urge to urinate. The most common cause of urge incontinence is involuntary and inappropriate detrusor muscle contractions. Involuntary actions of bladder muscles can occur because of damage to the nerves of the bladder, to the nervous system (spinal cord and brain), or to the muscles themselves. Multiple sclerosis, Parkinson's disease, Alzheimer's Disease, stroke, and injury - including injury that occurs during surgery - can all harm bladder nerves or muscles. People with functional incontinence may have problems thinking, moving, or communicating that prevent them from reaching a toilet. A person with Alzheimer's Disease, for example, may not think well enough to plan a timely trip to a restroom. A person in a wheelchair may be blocked from getting to a toilet in time. Conditions such as these are often associated with age and account for some of the incontinence of elderly women and men in nursing homes.