What is Headache?|
When a person has a headache, several areas of the head can hurt, including a network of nerves that extends over the scalp and certain nerves in the face, mouth, and throat. The muscles of the head and the blood vessels found along the surface and at the base of the brain are also sensitive to pain because they contain delicate nerve fibers. The bones of the skull and tissues of the brain itself never hurt because they lack pain-sensitive nerve fibers. The ends of these pain-sensitive nerves, called nociceptors, can be stimulated by stress, muscular tension, dilated blood vessels, and others triggers of headache.
Vascular headaches (migraines are a kind of vascular headache) are thought to involve abnormal function of the brain's blood vessels or vascular system; muscle contraction headaches appear to involve the tightening or tensing of facial and neck muscles; and traction and inflammatory headaches are symptoms of other disorders, ranging from brain tumor to stroke to sinus infection.
Some types of headache are signals of more serious disorders: sudden, severe headache; headache associated with convulsions; headache accompanied by confusion or loss of consciousness; headache following a blow on the head; headache associated with pain in the eye or ear; persistent headache in a person who was previously headache free; recurring headache in children; headache associated with fever; headache that interferes with normal life. Physicians will obtain a full medical history and may order a blood test to screen for thyroid disease, anemia, or infections or x-rays to rule out a brain tumor or blood clots. CTs, MRIs, and EEGs may be recommended. An eye exam is usually performed to check for weakness in the eye muscle or unequal pupil size. Some scientists believe that fatigue, glaring or flickering lights, the weather, and certain foods may trigger migraine headaches.
National Institute of Neurological Disorders and Stroke