Bedwetting: What Causes It?
It's a myth that laziness causes bedwetting. Millions of kids wet the bed -- but why? And how can you help
The Usual Bedwetting Suspects
Yet genetics only tells part of the story. Researchers have identified a
number of factors that likely contribute to bedwetting. "All of these are
debated, but each probably plays a role in some children," says Bennett,
Delayed bladder maturation. "Simply put, the brain and bladder
gradually learn to communicate with each other during sleep, and this takes
longer to happen in some kids," Bennett tells WebMD.
Low anti-diuretic hormone (ADH). This hormone tells the kidneys to
make less urine. Studies show that some kids who wet the bed release less of
this hormone while asleep. More urine can mean more bedwetting.
Deep sleepers. "Families have been telling us for years that their
children who wet the bed sleep more deeply than their kids that don't," says
Bennett. Research confirms the link. "Some of these children sleep so deeply,
their brain doesn't get the signal that their bladder is full."
Smaller "functional" bladder. Although a child's true bladder size
may be normal, "during sleep, it sends the signal earlier that it's full," says
Constipation. Full bowels press on the bladder, and can cause
uncontrolled bladder contractions, during waking or sleep. "This is the one
that's hiding in the background," says Bennett. "Once kids are toilet trained,
parents often don't know how often a child is going ... [they're] out of the
Bedwetting: When Is It Worth Worrying?
Bedwetting that's caused by medical problems is genuinely rare -- 3% of
cases or less, according to Bennett. Urinary tract infections, sleep apnea,
diabetes, spinal cord problems, and deformities of the bladder or urinary tract
-- all are worth mentioning, but probably not worrying over.
Medical causes of bedwetting are nearly always uncovered by simply talking
to a child and her parents, performing an exam, and testing the urine, says
"The vast majority of kids who are wet at night have nothing medically wrong
with them," he emphasizes.
Children who have gained nighttime bladder control, then "relapsed" into
bedwetting, are slightly more likely to have medical causes. Psychological
stress (such as divorce or the birth of a new sibling) is an even more common
Pediatricians don't diagnose primary nocturnal enuresis (the medical term
for bedwetting) until age 6. It's an arbitrary cutoff -- after all, 12% of
children wet the bed at that age. "It's really only a problem when either the
child or the parents start to think so," says Bennett.