Bedwetting is involuntary urination in children over 5 to 6 years old. It usually occurs at night. (See also incontinence.)

Children develop complete control over their bladders at different ages. Nighttime dryness is usually the last stage of toilet learning. When children wet the bed more than twice per month after age 5 or 6, we call it bedwetting or enuresis.

Children who were dry for at least 6 months and then started wetting again have secondary enuresis. The key here is to find what changed. It might be physical, emotional, or just a change in sleep.

When the child has never been dry, that is called primary enuresis. The cause is usually making more urine overnight than the bladder can hold and being a deep sleeper. The child's brain has not learned to respond to the signal that the bladder is full. It is not the child's or the parent's fault.

Physical causes are rare, but may include lower spinal cord lesions, congenital malformations of the genitourinary tract, infections of the urinary tract, or diabetes .

Bedwetting runs strongly in families. More than 5 million children in the U.S. wet the bed.

At age 5, more than 7% of` boys and 3% of girls wet. At age 10, 3% and 2% still do.

A physical examination may be performed to rule out physical causes. A urinalysis is indicated to rule out infection or diabetes.

X-rays of the kidneys and bladders and more invasive studies are not needed unless there is reason to suspect some other problems.

Doing nothing or punishing the child are both common responses to bedwetting. Neither helps. Waking the child once each night may give dry sheets and improve self-esteem, but won't speed the end of bedwetting. Without taking steps to solve the bedwetting, about 85 percent of children wetting this year will still be wetting next year. With the proper help, most children can be dry within 12 weeks.

Some children just need to drink less than 2 ounces in the 2 hours before bed to decrease the amount of urine made. If the wetting doesn't improve within 2 weeks, though, continuing this won't help.

Some children respond to star charts. Getting a star for dry nights can help the sleeping brain be alert for the bladder's signal. Again, if the wetting doesn't improve within 2 weeks, continuing won't help. Gently telling the child as he is falling asleep to be ready later for his bladder's signal may be useful.

Many children will stop wetting with just 30 minutes more sleep each night.

Most will be dry within 12 weeks with a bedwetting alarm that wakes the parents (and then they wake the child) when the bladder is full. Here, you will often NOT see a response within the first two weeks.

Prescription medications such as DDAVP are available to treat bedwetting by forcing the body to make less urine at night. They are easy to use and have quick results. They can be used short term for an important sleepover. To help outgrow bedwetting, however, they must be continued for at least 6 months beyond achieving dryness, and they are expensive.

With secondary enuresis, it is important to look for the cause before treating.

Getting pleny of sleep, avoiding too many fluids at night, and learning about how the bladder works at night will sometimes prevent bedwetting.