Bedwetting

The following list summarizes bedwetting's known causes and risk factors. Enuretic patients frequently have more than one cause or risk factor from the items listed below.

Most common causes

Most cases of bedwetting are PNE-type, which has two related most common causes

Neurological-developmental delay
This is the most common cause of bedwetting. Most bedwetting children are simply delayed in developing the ability to stay dry and have no other developmental issues. Studies suggest that bedwetting may be due to a nervous system that is slow to process the feeling of a full bladder.

Genetics
Bedwetting has a strong genetic component. Children whose parents were not enuretic have only a 15% incidence of bedwetting. When one or both parents were bedwetters, the rates jump to 44% and 77% respectively.Genetic research shows that bedwetting is associated with the genes on chromosomes 13q and 12q (possibly 5 and 22 also)

These first two items are the most common factors in bedwetting, but current medical technology offers no easy testing for either cause. There is no test to prove that bedwetting is only a developmental delay, and genetic testing offers little or no benefit.

As a result, doctors work to rule out other causes. The following causes are less common, but are easier to prove and more clearly treated:

Infection/disease
Infections and disease are more strongly connected with secondary nocturnal enuresis and with daytime wetting. Less than 5% of all bedwetting cases are caused by infection or disease, the most common of which is a urinary tract infection.

Physical abnormalities
Less than 10% of enuretics have urinary tract abnormalities, such as a smaller than normal bladder. Current data does support increased bladder tone in some enuretics, which functionally would decrease bladder capacity.

Insufficient anti-diuretic hormone (ADH) production
A portion of bedwetting children do not produce enough of the anti-diuretic hormone. As explained above, the body normally increases ADH hormone levels at night, signalling the kidneys to produce less urine. The diurnal change may not be seen until about age 10.

Psychological
Psychological issues (e.g., death in the family, sexual abuse, extreme bullying) are established as a cause of secondary nocturnal enuresis (a return to bedwetting), but are very rarely a cause of PNE-type bedwetting. Bedwetting can also be a symptom of a pediatric neuropsychological disorder called PANDAS. When enuresis is caused by a psychological or neuropsychological disorder, the bedwetting is considered a symptom of the disorder. Enuresis has a psychological diagnosis code (see previous section), but it is not considered a psychological condition itself. (See section on psychological/social impact, below)

Constipation
Chronic constipation can cause bedwetting. When the bowels are full, it can put pressure on the bladder.

Attention deficit hyperactivity disorder (ADHD)
Children with ADHD are 2.7 times more likely to have bedwetting issues.[

Stress
Stress is not a cause of primary nocturnal enuresis (PNE), but is well established as a cause of returning to bedwetting (secondary nocturnal enuresis). Researchers studying children who have yet to stay dry find "no relationship to social background, life stresses, family constellation, or number of residencies." On the other hand, stress is a cause of people who return to wetting the bed. Researchers find that moving to a new town, parent conflict or divorce, arrival of a new baby, or loss of a loved one or pet can cause insecurity, contributing to returning bedwetting.