Synonym: Yom Kippur headache, first-of-Ramadan headache
Criteria for fasting-associated headache:
(1) The person has been fasting >= 8 hours.
(2) The headache is diffuse and usually mild to moderate in intensity.
(3) Both of the following:
(3a) The onset of the headache was while the person was fasting.
(3b) The headache significantly improves after the person has eaten.
(4) No other diagnosis can explain the headache better.
Differential diagnosis:
(1) migraine headache
(2) caffeine withdrawal headache
A patient with a history of fasting-related headaches can avoid the headache by taking an analgesic prior to the fast.
