A disorder evolving from frequent episodic tension-type headache, with daily or very frequent episodes of headache, typically bilateral, pressing or tightening in quality and of mild to moderate intensity, lasting hours to days, or unremitting. The pain does not worsen with routine physical activity, but may be associated with mild nausea, photophobia or phonophobia.
Also indexed as
Chronic tension-type headacheChronic tension-type headache associated with pericranial tendernessChronic tension-type headache not associated with pericranial tenderness