Occasional headaches and brain fever are common and experienced by everyone at one time or another, but there are several types of headaches that are not so uncommon and can even be life-threatening if not treated promptly. If the headache is very severe and accompanied by hemiparesis or impaired consciousness, it may be a typical sign of a hypertensive brain hemorrhage, and patients with a history of hypertension should be alert. If the headache comes on rapidly, occurs within seconds or minutes, and is extremely severe distension or burst-like pain, accompanied by vomiting and cervical tonicity (spasmodic contraction and pain in the neck muscles, neck stiffness, and limited movement), then you should immediately realize that it may be a subarachnoid hemorrhage and call 120 emergency immediately. Patients with impaired consciousness should lie flat and turn their heads to the side to avoid asphyxiation caused by vomit and wait for the arrival of an ambulance. In case of respiratory and cardiac arrest, simple first aid can be given by artificial respiration and chest compressions.