TTH can be divided into:
- Infrequent: At least 10 episodes of headache occuring on <1 day/month on average (<12 days/year)
- Frequent: At least 10 episodes of headache occuring on 1-14 days/month on average for >3 months (≥12 and ≤ 180 days/year)
- Chronic: Headache occuring on ≥ 15 days/month on average for > 3 months (≥180 days/year)
Diagnostic criteria (B-D need to be fulfilled):
- Lasting hours to days, or unremitting
- At least 2 of the following 4 characteristics:
- Bilateral headache
- Pressing / tightening quality but not pulsating
- Mild to moderate intensity
- Headache not aggravated by routine physical activity
- Both of the following:
- No more than one of photophobia, phonophobia or mild nausea
- Neither moderate or severe nausea nor vomiting
- Not better accounted for by another ICHD-3 diagnosis
| Study | Reliability | Sn | Sp | LR+ | LR- |
| International Classification of Headache Disorder 3rd edition (ICHD-3) | NA | NA | NA | NA | NA |