There are many causes of sudden headache, as follows: 1. The most common ones are migraine, tension headache, cluster headache and low cranial pressure headache, which can cause sudden headache attacks and even nausea and vomiting, which are primary headache; 2. Headache caused by high blood pressure and some drugs, which are secondary headache; 3. can cause headache. In short, patients should not panic after sudden headache, they can go to a quiet and dim environment to rest first, if they do not see relief after rest, they must consult a doctor in time, ask the doctor to measure blood pressure, measure blood sugar and conduct relevant examinations, check some head CT, check some intraocular pressure, etc. to find the cause. If the cause of the disease can be found, prompt treatment. If these tests are found to be normal, primary headache, such as migraine, low cranial pressure headache, cluster headache or tension headache, can be considered. Patients themselves should improve poor lifestyle, do not stay up late, do not smoke, do not drink alcohol, do not drink excitatory drinks such as coffee and strong tea, live a regular life, stay optimistic, and ensure sleep.