Nighttime headaches: What causes them?

It's impossible to be certain of the cause of these headaches based only on your brief description. But they may represent hypnic headaches, sometimes called "alarm clock headaches." Hypnic headaches begin during sleep, awakening the person — usually at the same time every night. Some individuals also have daytime naps interrupted by the headaches.

This disorder most often occurs in people older than age 50. The pain can be mild to severe and usually lasts from 15 minutes to two hours, but occasionally longer. The exact cause isn't known.

A doctor can make a diagnosis of hypnic headaches based on an individual's medical history and signs and symptoms. Treatment may include:

• A dose of caffeine before bedtime
• Lithium
• Indomethacin, an anti-inflammatory medication

See your doctor if you have headaches that occur during sleep. Migraine and cluster headaches also can awaken a person from sleep. But they rarely occur only during sleep. Other serious causes of headaches during sleep include:

• Sleep apnea
• Giant cell arteritis, also called cranial arteritis, an inflammation of the arteries in the head
• Subdural hematoma, bleeding on the surface of the brain
• Brain tumor