Hiccup, or HICCOUGH, is caused by an involuntary contraction of the Diaphragm (q.v.), while the glottis is spasmodically closed. The inward current of air through the narrowed aperture, and its sudden arrest when the glottis closes, cause the characteristic sound. Usually the paroxysm only lasts for a few minutes, but it may sometimes extend to hours or days. The most common cause of hiccup is some disordered condition of the stomach. Very obstinate hiccup sometimes occurs in various diseases, especially fevers and diseases of the lungs and liver; and may be a very serious complication in consequence of the exhaustion it produces. Sometimes it has a nervous origin.
When the attack is slight it may often be stopped by making a very full inspiration, and then holding the breath as long as possible, the diaphragm being thus kept in a state of voluntary contraction. A draught of cold water, a start or blow, or strong pressure round the waist will sometimes give relief. In more obstinate cases a combination of camphor or of opium with chloroform, and the frequent swallowing of small rounded pieces of ice, are perhaps the most efficient remedies. Bismuth, mnx vomica, bromide of potassium, and many other drugs have also been recommended.