DIABETES INSIPIDUS.—A condition in which very large quantities of extremely thin urine are discharged. In cases of medium severity the quantity may vary from six to seven quarts in a day, but in severe cases it may increase to twice these amounts or more. In contrast to diabetes mellitus and to chronic inflammation of the kidneys, in which the quantity of the urine is generally also increased, the urine discharged in this disease does not contain any morbid constituents. In keeping with the great excretion, there is great thirst. As the supply of water rarely keeps up with the excre tion, the tissues of the body become impoverished in water. This is made manifest by dry skin and by the absence of all perspiration. Whereas mild or medium degrees of the disorder are frequently borne for decades without any marked disturbances, a certain loss of strength always becomes manifest when the disease increases in severity.
Diabetes insipidus, which is a very rare affection, generally appears very suddenly. Sometimes it accompanies the afflicted individual for life ; at other times it disappears after a shorter or longer period. The real causes
of the disease are not known. It develops most frequently in connection with other affections, such as influenza, pneumonia, typhoid fever, scarlatina, etc. In some instances the disease is thought to be due to an affection of certain areas of the brain, but in the majority of patients there is no cerebral disorder. Treatment consists in careful nutrition, intended to counteract the threatening loss of strength, with simultaneous careful atten tion to all other measures calculated to improve the condition of the body. Favourable results have been obtained in some instances by a very gradual restriction of the over-abundant supply of water. This, however, is a double edged measure, upon which one should never decide without the most careful medical surveillance. Not much is to be expected of medicines. The disease is by no means incurable, even if many cases are so malignant from the very beginning that they are refractory to all treatment.