A sudden and very painful headache may be related to trauma, or it may be due to high blood pressure, migraine and other causes. 1. Trauma: If you suffer a sudden accident, resulting in head trauma, it may cause headaches. You should consult a doctor in time, and give targeted treatment after diagnosing the cause by completing relevant examinations. 2. Hypertension: Especially for people with a history of high blood pressure, a sudden sharp rise in blood pressure due to excessive mood swings and anger stimulated by certain stressful events may cause a sudden headache, which may be accompanied by dizziness, nausea and other symptoms. 3. Migraine: If you have a history of migraine and fail to pay attention to daily care, such as not paying attention to head and face warmth when you go out in the cold winter, resulting in cold stimulation of the head and face, or a large amount of food such as chocolate, cheese, etc., it may trigger a migraine attack, which can lead to a sudden headache. Sudden headache may also be caused by other reasons, if the symptoms do not get better, you should consult a doctor in time.