Eat crayfish headache considerations related to allergies, infections, poisoning and other factors. 1. Allergy: some allergic people eat crayfish will produce an allergic reaction, such as abdominal pain, diarrhea, rash, headache, dizziness and so on. 2. Infection: If the crayfish is not clean or not processed thoroughly, it can cause bacterial infection or parasitic infection, leading to acute gastroenteritis, causing headaches. 3. Poisoning: some crayfish in the cleaning process using some special chemicals, if the chemical composition is too thick or not diluted clean will be poisoned, dizziness, headache, nausea, vomiting, coma and other symptoms. Eat crayfish headache should be taken seriously, timely medical care, clear cause for treatment.