Synonyms.—Polyuria; Hydruria; Hyperuresis; Diuresis.
Definition.—A constitutional disease characterized by an excessive flow of urine of low specific gravity, and devoid of sugar and albumin, thirst, and loss of flesh and strength.
Etiology.—Age predisposes to diabetes insipidus, it being more frequent during childhood and early maturity, the disease becoming more rare after reaching the age of thirty. Heredity also plays an important part. Weil notes twenty-three cases in a family running back four generations. It has occurred during' convalescence of acute infectious diseases, and is often associated with abdominal tumors, tuberculosis, and syphilis. The ingestion of large quantities of water or malt liquors, is not infrequently followed by polyuria.
Disorders of the nervous system, however, are more largely responsible than all other causes combined. Bernard discovered a spot in the floor of the fourth ventricle of animals, which, when irritated, is followed by polyuria. Tumors of the brain, blows on the head, great mental excitement, fright, sunstroke, apoplexy, and paralysis of the sixth nerve, have all been followed by diabetes insipidus. Epileptics not infrequently have this lesion.
Pathology.—No characteristic anatomical lesions are found. In some cases the bladder is hypertrophied owing to constant overdistention. The ureters and pelvis of the kidneys have been found dilated, due to backward pressure due to an overdistended bladder. The kidneys are sometimes enlarged and congested. Various lesions of the nervous system have been found, but none peculiar to polyuria.
Symptoms.—Diabetes insipidus may come on gradually or develop suddenly. When due to shock or traumatism, it develops quickly, otherwise it is insidious in its appearance. The patient's attention is first attracted to the disease by the frequent calls to urinate and the large quantity voided, and that he is compelled to micturate several times during the night. The urine is clear, light in color, and of low specific gravity, ranging from 1,001 to 1,008, and varying in quantity from three to thirty quarts every twenty-four hours. Thirst is a prominent symptom, and large quantities of water are consumed. The mouth, owing to deficient secretion of saliva, becomes dry, and the skin is dry and constricted. Usually there is but little disturbance of the digestive system, although persistent constipation, due to the excessive quantity of water voided, is a common feature.
The only complaint made by the patient is that of aching in the loins and weariness on slight exertion. Although there is gradual loss of flesh, there is not the emaciation that is seen in diabetes mellitus. The surface and the extremities are inclined to be cool, and a subnormal temperature is not uncommon.
The course of the disease depends to a great extent upon the primary lesion. Where due to tuberculosis or organic disease of the brain or abdomen, the general health fails, the patient becomes much emaciated, and the disease terminates fatally in from a few months to one or two years, while in idiopathic cases, the patient may live for years in comparatively good health.
Diagnosis.—The large quantity of urine voided, the low specific gravity and absence of sugar, enables one to recognize diabetes insipidus from diabetes mellitus, and the continued polyuria day after day enables one to recognize it from polyuria due to hysteria, which is always more or less transient.
Prognosis.—When due to organic lesions of the brain or abdomen, the prognosis is unfavorable. If idiopathic, the patient may live for years and enjoy comparatively good health, and a good per cent of cases will entirely recover.
Treatment.—The idiopathic form of the disease yields readily to medication, which is simple and positive.
Belladonna.—A belladonna plaster is ordered across the loins, and the specific tincture of belladonna given internally. Ten to fifteen drops of the specific tincture are added to four ounces of water, and a teaspoonful given every three hours. Where there is a feeble capillary circulation, this remedy will not disappoint in its action.
Rhus Aromatica.—This is an excellent remedy in polyuria, but should be given in fifteen to twenty drop doses, four times a day. Ergot in drop doses every hour is also a good agent in many cases. A general tonic treatment is frequently very beneficial in bringing; about a cure. In addition to the tonic diuretics, hydrangia, collinsonia, hamamelis, achillea, and like remedies, the administration of the compound tonic mixture (the triple phosphate of iron, quinia, and strychnia), in half teaspoonful doses, will give good results.
The diet should be nourishing, but easily digested, and as little fluid taken as is consistent with good health. Moderate exercise in the open air, and a sponge-bath daily, is to be advised. An equable climate assists materially in effecting a cure.