Mistake: Napping when your baby naps

This classic advice applies only when you're getting up every few hours at night to feed your newborn. Once he's a few months old and sleeping longer  -- and especially if he's sleeping through the night and you are, too  -- you don't need to nap much. Babies should get about 15 hours of sleep in a 24-hour period. You need about eight. If you snooze for three hours during the day, you may have trouble sleeping at night.

A better approach: If you're tired, take a catnap at about the same time every day. Ten to 20 minutes will help you feel refreshed for another couple of hours. Doze much longer than that and you can wake up feeling groggy and worse than you did before.

Mistake: Ignoring your health issues

You'd never miss a well-baby checkup, but when was your last physical? Many treatable conditions interfere with a good night's sleep, including PMS, asthma, restless leg syndrome, and bladder problems. (Going to the bathroom once in the middle of the night is normal; going three or four times is not.) About 50 percent of people who have chronic insomnia have an underlying psychiatric issue, such as anxiety disorder or depression.

A better approach: See your doctor if you think any health concerns are affecting your sleep. All of the problems mentioned above can be helped with medication and lifestyle changes. Says Nancy Collop, M.D., spokesperson for the American Academy of Sleep Medicine, "You don't have to suffer."