Stress Urinary Incontinence
Stress urinary incontinence (SUI), also known as effort incontinence, is due essentially to insufficient strength of the pelvic floor muscles. It is the loss of small amounts of urine associated with coughing, laughing, sneezing, exercising or other movements that increase intra-abdominal pressure and thus increase pressure on the bladder. The urethra is supported by fascia of the pelvic floor. If this support is insufficient, the urethra can move downward at times of increased abdominal pressure, allowing urine to pass.
Resources:
http://en.wikipedia.org/wiki/Urinary_incontinence
http://www.nlm.nih.gov/medlineplus/ency/article/000891.htm
http://kidney.niddk.nih.gov/kudiseases/pubs/uiwomen/
http://www.mayoclinic.com/health/urinary-incontinence/ds00404/dsection=treatments-and-drugs