Nighttime headaches: What are the causes?

I am 67 years old and in good health. I often wake up from sleep with a severe headache. This even happens during my afternoon nap. The headache goes away after a while. I don't have headaches during my waking hours. Should I be concerned?

- No name / No state given

Mayo Clinic neurologist Jerry Swanson, M.D., and colleagues answer select questions from readers.

Answer

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 only during sleep, usually awakening the person at the same time every night. Some people also have daytime naps interrupted by hypnic headaches.

This disorder most often occurs in people older than age 50. The pain can be mild to moderate 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. Migraines 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