It is possible that drinking too much coffee can cause headaches. Patients who have headaches after drinking coffee are themselves suffering from migraine, a functional headache whose pathogenesis is mainly due to vasoconstriction and dilation dysfunction, or abnormal secretion of 5-hydroxytryptamine neurotransmitters in the brain and trigeminal nerve dysfunction, and this disease has a certain genetic susceptibility. Migraines may be triggered when patients drink coffee, strong tea, or eat chocolate, substances that increase neuroexcitability, probably because of the ability of these substances to affect vasoconstriction and 5-hydroxytryptamine secretion. Patients with this disease should avoid such substances, as well as alcohol, cheese products, cured meats, and high-fat foods.