There are 2 forms of tension-type headaches. The episodic form occurs on fewer than 15 days per month. The chronic form occurs on 15 or more days per month. The cause of tension-type headache is uncertain. It may be associated with contraction of muscles in the neck and head, and the triggers of tension-type headache may include poor posture (such as from prolonged computer use or sleeping in an unusual position), smoking, fatigue, and stress. Sometimes, a tender point is present at the neck and scalp. Tension-type headaches usually start at younger ages (such as in the 20s) and rarely after age 50 years.