_Causes of Headache._—These may be classified into those in which the blood is at fault; reflex causes; various nervous disorders; and organic diseases. The blood may be impoverished, as in the case of anemia, where there is a deficiency in hemoglobin; but by far the most frequent cause of headache is where the blood is disordered, as in gout, rheumatism, kidney diseases, diabetes, and the infectious fevers and malaria. Among the more common reflex causes are eye-strain, especially errors of refraction; disorders of digestion, particularly constipation; and pelvic disorders, as in inflammation of the pelvic viscera. Functional diseases of the nervous system causing headache are overwork, neurasthenia, hysteria, epilepsy, and neuritis. Among the most common of the organic diseases is arteriosclerosis; other diseases are meningitis and brain tumors. _Symptoms._—The pain is often dull in character and rendered worse by stooping; the location of the pain depends on the cause of the headache. The most common variety is over the forehead or eyes. In eye-strain the pain may either be in the front or back of the head. In indigestion, the pain is most frequently over the eyes, but it may also be on the top of the head. In anemia the pain may be either frontal or diffuse. In pelvic disorders the pain is generally at the base of the brain, though it is sometimes in the top of the head. Neuralgic headaches are generally characterized by sharp paroxysmal attacks, located in the temporal regions, and associated with pain in other parts of the body. It is perhaps most frequently caused by anemia. In hysteria the headaches are characterized by a circumscribed pain—it has been likened to the driving of a nail into the head. In migraine the pain is paroxysmal and intensely severe; it is frequently caused by some poison in the blood, as in autointoxication, due to failure of proper regulation of the bowels, also by pelvic disorders. _Treatment._—The treatment is constitutional, and is based on the removal of the cause. First, there should be a regulation of the diet, a free evacuation of the bowels, and their proper regulation. In every case of headache there should be an examination of the urine. Often there is some congestion of the kidneys where it is least suspected. If the headache is persistently made worse by reading or sewing, the patient should be referred to a competent oculist. An inquiry should always be made into the condition of the menstrual function, backache, and leukorrhea. Any marked disorders here will necessitate a gynecologic examination. For the immediate relief of migraine, the patient should go at once to bed and drink a glass of hot water; sometimes a cup of hot tea gives great relief. No food should be taken for from six to twelve hours, according to the severity of the case. The room must be kept dark and quiet and the head high.