When encountering adult nocturnal enuresis (bedwetting), understanding the underlying biological mechanisms is the primary requirement for successful treatment. Two main physiological factors play a role in this process: bladder capacity and hormonal balance. In urology clinics, treatment methods are determined by analyzing these two critical values of patients.
ADH: The Hormone Regulating Nocturnal Urine Production
Under normal conditions, as the body enters sleep, the pituitary gland in the brain secretes Antidiuretic Hormone (ADH), also known as Vasopressin. This hormone signals the kidneys to "concentrate urine and reduce production." In many adults experiencing nocturnal enuresis, nocturnal secretion of this hormone is insufficient or fails to increase. Consequently, the kidneys produce excessive urine throughout the night (nocturnal polyuria), exceeding the volume the bladder can hold.
Functional Bladder Capacity
Another important factor is the physical and functional flexibility of the bladder. In individuals with a smaller-than-normal bladder capacity or involuntary contractions during sleep (detrusor overactivity), even normal nocturnal urine output can overfill the bladder and cause sleep incontinence. This issue can be detected by measuring bladder capacity through urodynamic studies.