Call for emergency help immediately if you think a friend or family member may be having a stroke. Call your doctor promptly if you develop a severe headache with vomiting. Headaches should also be evaluated by your doctor if they occur frequently or are accompanied by other symptoms, such as nausea, vomiting, weakness or numbness in any part of the body. If you take warfarin, report a new headache to your doctor.
If you have a sudden, very severe headache that goes away, it is still important to discuss this with your doctor. Sometimes blood leaks briefly from a blood vessel one or more times before a subarachnoid hemorrhage occurs. The headache this leak causes is called a sentinel headache. If this is followed by a more severe subarachnoid hemorrhage, the hemorrhage usually happens between 6 and 20 days after the headache. Your doctor may be able to provide treatment after a sentinel headache that can prevent more serious bleeding.