The observations that disulfiram, which blocks the transformation of ACD into acetic acid, in combination with alcohol intake, but not per se, increases the possibility of developing headaches [6], and that when Asians, with loss of function ALDH2 mutations, consume alcohol, acetaldehyde accumulating in the blood can lead to physical discomfort and various symptoms, including headache [49], further strengthen the role of ACD as a headache-provoking agent. Here, ALDH2 is linked to Headache.