Headaches Explained A headache is a symptom, not a disease. A headache is rarely the symptom of a serious illness, but severe or frequent headaches can be exhausting and can affect daily life. There are three basic types of headaches: vascular headache, muscle contraction headache, and inflammatory headache. Vascular headaches The vascular headache occurs when blood vessels in the head enlarge and press on nerves, causing pain. The most common vascular headache is the migraine(偏头痛). One theory about migraine headaches is that they occur when the blood vessels in the head expand and press on the nerves, causing pain. Another theory is that they result from the blood vessels constricting and thus blocking blood flow to parts of the brain this may cause the visual suffering that often accompany or precede a migraine headache. The blood vessels then become full of blood and press on surrounding nerves, causing pain. Women are more easy to suffer migraines than are men, and a certain personality type compulsive, perfectionist, and very success oriented seems to be more likely to be affected with migraine headaches. Causes A number of physical and emotional factors may contribute to migraine headaches. Migraines may be triggered by a sharp reduction in caffeine intake or by allergies to certain foods. Emotional stress can also cause migraine headaches, as can drinking alcohol, smoking, or an interruption in routine eating and sleeping habits (all of which may be responsible for 'weekend' headaches suffered by some patients). Cyclical, seasonal, or emotional factors may also be associated with the tendency to develop migraine headaches. A tendency to develop this type of headache may be inherited. Symptoms The predominant symptom of a migraine headache is a sharp pain on one or both sides of the head. Paleness, sweating, and sensitivity to light may accompany the pain. A warning sensation may indicate an approaching migraine headache. Before the pain begins, some individuals may see flashing lights or 'shooting stars', hear noises, or have an uncomfortable feeling in the arms or legs. Diagnosis Vascular headaches are diagnosed by a careful review of the circumstances surrounding the headaches as well as by a physical examination to rule out any other disorder that might be causing the symptoms. Elimination tests may be done to identify the exact cause of migraines suffered by people who seem to react to certain foods or changes in eating and sleeping habits. In an elimination test, all the substances that are suspected of causing the trouble are eliminated and then reintroduced one at a time to identify the specific cause of the migraine headaches. Treatment Treatment of a migraine already in progress usually consists of a drug therapy program chosen from a variety of painkillers, tranquilizers, and special prescribed medications. Prevention Prevention of migraines is possible with several types of medication. Antidepressant drugs and beta-blockers have been shown to prevent migraines in some patients. These drugs work in the body to block what are called the beta effects, one of which is expansion of the blood vessels. While it is not yet known exactly how these drugs provide relief research suggests that they act by preventing the initial constriction of blood vessels that causes migraine. Muscle Contraction Headaches A muscle contraction headache occurs when muscles of the face, neck, or scalp remain tightened for long periods of time. These muscles are then said to be in spasm(痉挛). A tension headache is an example of a muscle contraction headache. Causes A muscle contraction headache usually occurs after a specific event that has caused the muscles to tense. The tension is then translated into physical discomfort in the form. of a clenched jaw, aching neck,