And she hated the plastic sheet that accompanied family vacations. For many such children, like Patsy, the consequences are humiliation and damaged self-esteem. Bed-wetting is considered normal up to age 5. When the problem persists, however, a visit to the doctor is in order. The precise cause of bed-wetting is unknown.
Most cases appear to be due to delayed physical development.
Bladder capacity may be less than half what is considered normal for the child's age. Some researchers, in fact, have argued that boys aren't normally dry at night until age 8. Several studies point to a genetic link in enuresis. But the figure dropped to 44 percent when only one parent had wet the bed in childhood. By contrast, when neither parent had enuresis, only 15 percent of the children did.