Sleep Apnea and Headaches:
Sleep Apnea Headaches are fairly typical in their presentation. Morning headaches for someone with obstructive sleep apnea usually indicates the condition is at least moderate if not severe. The headaches result from significant changes within the bloodstream as a result of airway obstruction.
When a person suffers from Obstructive Sleep Apnea, the apneas (stoppage of breathing) that occur during sleep cause changes in blood oxygen and carbon dioxide levels. When you block the airway, and keep the lungs from exchanging air in and out, two things happen. First, carbon dioxide is trapped in the lungs and cannot get out. Thus, carbon dioxide levels increase within the bloodstream. The second event is that oxygen cannot get in, and its blood level drops. The cause of morning headaches, however, is the rise in carbon dioxide.
When Carbon dioxide levels rise, blood vessels in and around the head will dilate. This dilation results in a migraine-like headache that is irritating and throbbing. There are important differences between this headache and migraines though.
Sleep apnea headaches are usually on both sides of the head rather than just one side. Furthermore, sleep apnea headaches usually subside within thirty minutes of waking up. This headache reversal occurs because once you are awake, the lungs can move air in and out, and the carbon dioxide level returns to normal. Sleep apnea headaches quickly resolves after the normal exchange of air. Unfortunately, migraines can last for hours if not days.
In order for carbon dioxide to increase during sleep apnea events, the degree of obstruction typically has to be significant. For this reason, morning headaches are more likely to occur with increasingly severe sleep apnea patients. Although, if patients already have other heart and lung conditions, lesser degrees of sleep apnea may cause morning headaches.