A headache after eating greasy food may be caused by psychological factors, migraine and other reasons. 1. Psychological factors: greasy food is easy to make people psychologically averse to it due to its poor taste, thus leading to headaches. 2. Migraine: Greasy food may stimulate the original migraine patients to trigger migraine, thus headache symptoms, patients may also be accompanied by dizziness, nausea, vomiting, pallor and other symptoms. In addition to triggering migraine and psychological discomfort, long-term consumption of greasy food may also lead to increased blood lipids, which may lead to cardiovascular and cerebrovascular diseases and other health problems, so it is recommended to minimize or not to eat greasy food. If patients experience severe or persistent headaches after eating greasy food, they should go to the hospital in a timely manner to identify the cause and get targeted treatment.