ICHD-3 Criteria (Indomethacin-Responsive Headaches)
Applies the ICHD-3 criteria for the two indomethacin-responsive headaches.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Number of attacks
- 30
- Attack duration, minutes
- 15
- Attacks per day
- 8
- Miosis or ptosis
- Yes
- Absolute response to indomethacin
- Yes
- No better ICHD-3 explanation
- Yes
Result: 3.2 Paroxysmal hemicrania
The tool opens with these values already filled in. Replace them with your own.
What the result means
- 3.2
- At least 20 attacks of severe one-sided orbital, supraorbital or temporal pain lasting 2 to 30 minutes, MORE than 5 a day.
- 3.4
- One-sided headache present for more than 3 months, with exacerbations of moderate or greater intensity.
- Shared C
- Either or both: at least one ipsilateral cranial autonomic sign, or restlessness or agitation.
- The criterion that is a drug
- BOTH require an ABSOLUTE response to therapeutic indomethacin. It is a diagnostic criterion, not a consequence, so neither can be diagnosed before an adequate trial has been done and worked.
- Dose
- ICHD-3 notes that in an adult, oral indomethacin should start at at least 150 mg daily and rise if needed to 225 mg daily.
- Versus cluster
- Paroxysmal hemicrania is the diagnosis most often mistaken for cluster headache. Shorter and more frequent: 2 to 30 minutes more than 5 a day, against 15 to 180 minutes up to 8 a day.
- One asymmetry
- Hemicrania continua accepts aggravation of the pain by movement as an alternative in criterion C. Paroxysmal hemicrania does not.
What you enter
- Absolute response to indomethacin
- Number of attacks
- Attack duration, minutes
- Attacks per day
- Continuous one-sided headache
- Months present
- Exacerbations of moderate or greater intensity
- Conjunctival injection or tearing
The other 7 fields
- Nasal congestion or rhinorrhea
- Eyelid edema
- Forehead and facial sweating
- Miosis or ptosis
- Restlessness or agitation
- Pain worse with movement (3.4 only)
- No better ICHD-3 explanation
How this is calculated
Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38(1):1-211, sections 3.2 and 3.4. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.