Stress Incontinence is caused by any movement that puts pressure on the bladder. In females, if the pelvic walls that hold the bladder in place become weakened, the bladder slips toward the vagina, weakening the sphincter muscle that holds the bladder closed. This can be caused by the pressure of an unborn baby, when the uterus leans on the bladder from the weight of the baby and causes the bladder to leak or empty completely. Also, laughing or sneezing can trigger it, if there is already a weakness. In males, stress incontinence is caused when the prostate enlarges, thereby placing pressure on the urethra.
Sphincter muscles become overactive, causing leaks or emptying.
This is a tendency brought on by anything from nervousness to a stroke, to Parkinson's disease, multiple sclerosis or a spinal cord injury. Some people have both urge and overflow incontinence. It is not caused by a problem in the urinary tract. This chemical is also found in sanitary napkins, but in smaller amounts, so it's safer using dryness aids meant especially for bigger spills. They come in all sizes, from light absorbency to heavy or overnight strength.