Eating garlic headache is mostly caused by allergic phenomenon or induced migraine attacks. 1. Allergic phenomenon: garlic belongs to the spicy and stimulating food, some people are allergic to garlic, in addition to headaches, there may be rashes and nausea and other gastrointestinal symptoms. If there is no other discomfort, it is usually not a big problem, just leave the allergen. 2. Induced migraine attacks: garlic is a spicy and stimulating food, consumption may induce acute attacks of migraine, often accompanied by nausea, vomiting symptoms. Eating garlic headache may also be caused by other reasons. Usually, it can be treated without special treatment by stopping consumption. If accompanied by other discomforts, or symptoms are serious, it is recommended to consult a medical professional in a regular hospital.