Diabete's (Gr., lit. 'a syphon,' from diabainō, 'I go or flow through'), a disorder of the general system, of which the principal symptom is a greatly increased flow of urine. Diabetes is of two distinct kinds: the one, diabetes insipidus, is a mere exaggeration of the water-excreting function of the kidneys, accompanied by extreme thirst, and hence called polydipsia (Gr., 'excess of thirst') by some authorities; the other is a more complex disorder of the assimilation, consequent on the formation first, and the excretion by the kidneys afterwards, of an enormous excess of animal sugar (see SUGAR), the sugar being found in excess not only in the renal excretion, but in the blood, and in nearly all the secretions which have been examined. The pathology of this disease, called diabetes mellitus (Lat. mel, 'honey'), is very obscure, notwithstanding the numerous recent physiological researches which tend to throw light on the development of sugar in the animal organ- ism, especially in the liver, and which must undoubtedly be regarded as bearing on the solution of the problems connected with this disease. Unhappily, the cure of it is still entirely unknown, except in so far as it may be controlled or retarded by good management of the diet, drink, and clothing. The course of the disease, however, is very different at different periods of life. Before middle age it is severe, progressive, and almost invariably fatal. After that period precisely similar symptoms often appear, especially in gouty persons, but are so much less dangerous, and so much more easily controlled, that many authorities are unwilling to place them in the same class as true diabetes. All diabetics are subject to progressive emaciation, and they often become subject to a chronic disease of the lungs, closely resembling true tubercular Consumption (q.v.); it is chiefly in warding off this termination, or some other more quickly fatal, and in mitigating the symptoms of the malady, that the medical art can be of service.
The first fact observed in cases of diabetes is usually the increased flow of urine, when it becomes so great as to amount to a practical inconvenience; and also a considerable increase of the appetite, and an unquenchable thirst, which rarely fail to accompany the disease from the beginning, but often do not attract attention, or at least suggest the idea of anything wrong, till an advanced stage of the disorder. When the patient demands medical assistance he is usually somewhat thin; the pulse is quiet, the skin cool, the heat of the surface, indeed, habitually rather low and easily depressed. There is often a complete absence of perspiration, which gives a peculiar feeling of harshness to the surface, especially of the palms of the hands. With these symptoms the first approaches of pulmonary disease may concur. In the very last stages there is sometimes dropsy of the feet; and the urine may be natural in quantity, or even diminished. For the other characters of diabetic urine, see URINE. Diabetic persons bear excitement and fatigue, either mental or bodily, extremely badly; and imprudence in this respect is not unfrequently followed by sudden or rapid collapse and death. The treatment consists mainly in removing from the diet, as far as consistent with comfort and due nourishment, everything which easily turns to the formation of animal sugar in the system, especially all excess of farinaceous food. The complete suppression of sugar-forming food, however, as recommended long ago by Rollo, has not been found possible in practice in the majority of cases. Bread composed of gluten of wheat without starch, or bran-cakes baked with eggs, or biscuits made of almonds, have been strongly recommended; and in most of the great capitals, as London and Paris, bakers may be found who regularly furnish bread suitable for this unfortunate class of sufferers; indeed, any intelligent baker who will take the trouble may, under medical direction, be got to manufacture such bread when required; or it may be ordered in the form of cakes and biscuits, in quantities at a time, from London houses. It is of importance, however, that it be ascertained that the bread or flour supplied is really suitable; for Dr Pavy, one of the chief authorities on this disease, ascertained that some of the so-called foods for diabetics contain little less starch than ordinary bread. Saccharin (q.v.) has lately been of great service to diabetics, as it supplies the flavour of sugar without its objectionable properties. Medicines proper should be used only under the advice of the physician. There is no specific, and the unguarded use of strong remedies is to be condemned. Of all medicines that have been used, however, opium and morphia have been found most frequently use- ful in delaying the progress of the disease. Flannel should be worn next the skin, and the languid function of the cutaneous perspiration aided by the warm bath, especially, perhaps, the vapour bath—e.g. that form known as the Russian bath. The Turkish bath, which abstracts a large quantity of water through the skin, is less suitable to such cases.