- Fit the diagnostic criteria for CTTHs: headache occurring for 15 days a month or more, for a period of more than 3 months a year and lasts for hours or may be continuous. The headache should have at least one of the following characteristics: 1. bilateral location; 2. pressing/tightening (non-pulsating) quality; 3. mild or moderate intensity, 4. aggravated by normal physical activities such as walking or climbing stairs; and at least one of the characteristics in the following categories: 5.1. photophobia, phonophobia or mild nausea, and 5.2. moderate or severe nausea or vomiting ; and