About one in 10 people in America have chronic insomnia – a condition that costs the nation's economy $30 billion a year in lost productivity, the National Sleep Institute estimates.

Mary Dischert reports the problem commonly suffered by chronic-insomnia sufferers: She can fall asleep but cannot stay asleep.

"I wake up many times during the night. I never get a continuous night's sleep," Dischert said. "I wake up nine or 10 times during the night, and my sleep is continuously interrupted."

Insomnia can lead to depression, a weakened immune system, memory loss, cardiovascular disease and increased weight gain.

Dischert takes a prescription sleep medication, but said she does not want to stay on it – something with which doctors agree.

Changing your habits, such as your wake-up time, is a more effective course of action, doctors said.

"Having a stable daytime awakening is very important in keeping your body's time clock fixed, and that's critical," Dr. Joseph Ojile, a sleep specialist at the St. Louis University of Medicine, said.

Those who lack sleep should go to bed at the same time each night, Ojile said. They should also avoid watching television, listening to the radio or even reading while in bed, he said.

"Those tasks should be done elsewhere, so that your bed is the cue to go to sleep," Ojile said.

You should also avoid exercise less than four hours before bedtime. Do not drink caffeine or alcohol before going to bed.

Lying in bed awake for long periods is another often unexpected problem, Ojile.

"If that individual is lying in bed for, say, eight or 10 hours but only sleeping five, their sleep becomes very inefficient," he said. "Their body gets used to lying in bed and not sleeping."

At the sleep center in St. Louis where Ojile works, patients are told to sleep for only a few hours until their sleep duration improves. Then doctors lengthen their sleep time by hour at a time.

Chronic insomnia is a problem worth tackling with the help of professionals, Ojile urged, because sleep – or the lack of it – affects every aspect of our health.