What causes bed wetting?

 What causes bed wetting at night?

Bed wetting is a complex issue in the adult and can have multiple causes. Unlike children, some adults with bed wetting also have a problem with day time wetting. There is some evidence that adult bed wetting may have a genetic link. If one has either one or both parents who have had a problem with bed wetting, the chances are much higher that you will also be affected with this problem.

In some adults the hormone that controls urine production (ADH) may be absent or secreted in low amounts. Absence of the hormone ADH causes the kidney to constantly pass urine in the bladder. Other individuals may have a very sensitive bladder. As soon as the bladder starts to fill with urine, it sends signals to the brain to empty it. This leads to frequent urination and bed wetting. 

There are other individuals who have been involved in trauma and develop over activity of the bladder muscle. This causes the bladder to spontaneously contract and empty the bladder. Two substances which are commonly found to increased bladder over activity are caffeine and alcohol.
Medications like the diuretics for the treatment of blood pressure can also cause bladder muscle over activity and lead to spontaneous passage of urine. 

Other medications that can lead to bedtime wetting include the anti-psychotics like risperidone and thioridazine.  

Other common causes of secondary enuresis may include diabetes mellitus, urinary tract infections, kidney stones, neurological disorders (like stroke), anatomical abnormalities of the bladder or ureter, prostate cancer, benign prostatic hypertrophy and obstructive sleep apnea.  Adult bed wetting in rare circumstances can also be caused by emotional stress or severe anxiety.
Unlike children, adults with bed wetting need a thorough examination to rule out a cause which can be treated.