More than 50 percent of all cases of chronic insomnia are caused by an underlying physical condition. Many insomniacs are afflicted by a condition known as Periodic Leg Movements During Sleep, in which frequent and involuntary leg movements severely disrupt the victim's slumber. Breathing difficulties during sleep, like the one they found in me, are another common culprit. Chronic pain and plain old heartburn might also be to blame.
Psychological factors — persistent stress, depression and anxiety, for example — are also potent sleep wreckers. And a range of behavioral considerations — a sedentary lifestyle; an erratic sleep schedule (due to shift work, for example); and the use of caffeine, nicotine or alcohol, even in moderate amounts — can do real harm to your slumber.
Keep in mind that transient bouts of sleeplessness, due to temporary, situational stresses, are not uncommon. (Kids might have trouble sleeping just before the school year starts; adults may lose sleep over family frictions, bereavement or trouble at work.) This type of insomnia usually ends when the stresses are resolved or accommodated.
But if your sleep trouble lasts longer than a month and affects the way you feel and function during the day, you should ask your doctor about a referral to a sleep-disorder specialist.