Light Bladder Leaks or Stress Urinary Incontinence (SUI) is the involuntary loss of urine when performing activities that put stress on your urinary tract - running, coughing, or lifting. Light bladder leaks are believed to be caused by the weakening of the pelvic floor muscles that support the bladder and the muscles that help regulate and control the release and flow of urine. The weakening of these muscles can be caused by years of high impact activity, aging, or obesity. Another cause of SUI that women may experience is childbirth. Approximately 30% of women will experience light bladder leaks within 5 years of their first vaginal birth.