July 17, 2001 -- Those frequent morning headaches may not be the biggest of your problems. People who wake up often with headaches -- especially snorers -- may suffer from a disorder called sleep apnea, according to research presented last month in New York at the 10th International Headache Congress.
There are two types of sleep apnea. Obstructive sleep apnea is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses and closes during sleep. In central sleep apnea, the airway is not blocked but the brain fails to signal the muscles to breathe.
Because breathing stops so often, the person does not receive sufficient oxygen, causing carbon dioxide to build in the blood. This affects the nervous system as well as blood flow to the brain, causing headache as well as memory and mood changes, says Jeanetta Rains, PhD.
And the alteration in blood oxygen levels increases risk for cardiovascular problems, says Rains, director of the Center for Sleep Evaluation at Elliot Hospital in Manchester, N.H., and adjunct assistant professor of psychiatry at Dartmouth Medical School in Lebanon, N.H.
In her study, Rains analyzed the various complaints of more than 800 patients being tested for sleep-related problems.
Thirty-five percent complained of morning headaches, and 19% had morning headaches that occurred daily or nearly daily. Of those complaining of frequent morning headache, 67% were diagnosed with sleep apnea.
Of the people who had frequent morning headaches and who snored, 81% had sleep apnea.
Another study presented at the meeting, by Ann Scher, PhD, from Johns Hopkins School of Public Health in Baltimore, found that people with chronic daily headaches are 2.5 times more likely to snore than people who don't have daily headaches.
While snoring is often recognized as a symptom of sleep apnea, most people -- even physicians -- do not associate headaches with sleep disorders, says Rains. "Very often these people go to a doctor thinking it's the headaches that are disturbing their sleep," rather than thinking of the headaches as a symptom of poor sleep.
"The bottom line is that people who complain of headaches -- especially morning headaches -- may have a sleep disorder," Michael Thorpy, MD, director of the sleep disorders center at Montefiore Medical Center and associate professor of neurology at Albert Einstein College of Medicine, both in New York, tells WebMD. And Rains agrees, urging people who suffer from morning headaches to seek help.
Sometimes, treating the sleep disturbance leads to resolution of headaches, says Thorpy. "It doesn't happen in every case, but it does happen in some."
But keep in mind that sleep problems are not the sole cause of headaches, says David Haas, MD, a neurologist at SUNY at Syracuse. "There are many more causes of headaches than sleep problems."