A. Headache, in a person affected by a primary headache disorder and with the characteristics of that headache type, fulfilling criterion C
B. Absorption of a nitric oxide (NO) donor has occurred
C. Evidence of causation demonstrated by both of the following:
1. headache has developed within 2-12 hr after exposure to the NO donor, and after NO is cleared from the blood
2. headache has resolved within 72 hr after exposure
D. Not better accounted for by another ICHD-3 diagnosis.