Overactive Bladder Health Center

The cause of overactive bladder is damage to the nerves responsible for sending messages between the bladder and the brain. This nerve damage can occur for a number of reasons, including childbirth, brain or spinal cord infections, diabetes, stroke, accidents that injure the brain or spinal cord, multiple sclerosis (MS) and heavy metal poisoning. 

In men, problems with the prostate gland can cause overactive bladder. An enlarged prostate may squeeze the urethra, the tube that carries urine and semen from the body, resulting in a weak urine stream. This can cause urgent needs to urinate followed by accidental leakage, especially at night. 

In women, weak pelvic muscles may trigger overactive bladder. During pregnancy and childbirth, female pelvic muscles can become stretched and weak, making them harder to control. Weak muscles make the bladder sag out of proper position, which can stretch the opening to the woman's urethra. 

Excess weight, urinary tract infections and high intake of caffeine, alcohol or sleep medication may also cause overactive bladder by dulling nerves, filling the bladder too quickly or putting pressure on the bladder.