DROPSY (contracted from the old word hydropisy, from the Greek _____, water, and _____, the appearance) signifies a collection of simple serous fluid in all or any of the cavities of the body, or in the meshes of its tissues. Dropsy of the subcutaneous connective tissue is termed osdema when it is localized and limited in extent; when more diffuse it is termed anasarca; the term cedema is also applied to dropsies of some of the internal organs, notably to that of the lungs. Hydrocephalus signifies an accumulation of fluid within the ventricles of the brain or in the arachnoid cavity; hydrothorax, a collection of fluid in one or both pleural cavities ; hydro-pericardium, in the pericardium ; ascites, in the peritoneum ; and, when anasarca is conjoined with the accumulation of fluid in one or more of the serous cavities, the dropsy is said to be general.
Dropsy is essentially a symptom and not a specific disease, and ought not to be confounded with inflammatory exudations of a serous character. The transudation is a mere filtrate from the blood produced by increased intravascular pressure, of local or general origin, and occur-ring through the walls of the capillaries or smaller venules. Its specific gravity varies from 1 -008 to 1-014; it is alkaline, occasionally neutral, very rarely feebly acid; it is not the liquor sanguinis, but merely water holding in solution a varying proportion of the constituents of the blood serum, chiefly the saline constituents, and of these notably the chloride of sodium, occasionally urea, sometimes cholestrine, always more or less albumen, and a proportionate amount of fibrogenous matter. It may be colourless, greenish or reddish from the presence of blood pigment, or yellowish from the presence of bile pigment; transparent, or opalescent, or milky from the presence of fatty matter derived from the chyle. The membrane from which the dropsical fluid escapes is healthy, or at least not inflamed, and only somewhat sodden by long contact with the fluid the morbid condition on which the transudation depends lying elsewhere. The occurrence of dropsy is favoured by a watery condition of the blood due to imperfect nutrition, the pre-occurrence of acute disease, or the long continuance of exhausting discharges, as of albumen in Bright's disease, <fcc. This watery condition of the blood not only pre-disposes to dropsy, but also lends active aid in producing it by enfeebling the heart and thus disturbing the relations of the intravascular pressure. The active agents in the production of dropsy are whatever increases the intravenous blood pressure locally or generally. Obstruction to the centripetal venous current by thrombosis of the veins, by the pressure of hyperplasic connective tissue, as in hepatic cirrhosis, by the pressure of tumours either pathological, as aneurisms, cancerous or tubercular masses, or physiological, as a gravid uterus or a mass of faeces, or by the mere weight of the body in certain positions, as the sedentary, are efficient causes in the production of local dropsies. These are also more rarely brought about by thrombosis, or compression of the lymphatics, or of the thoracic duct, and this partly directly and partly indirectly by acting on the venous blood stream. The active agents in the production of general dropsy are diseases of the heart, the lungs, and the kidneys. The natural tendency of all diseases of the heart is to transfer the blood pressure from the arteries to the veins, and, so soon as this has reached a sufficient degree, dropsy in the form of local cedema commences to appear at whatever may be the most depending part of the bodythe instep and ankle in the upright position, the lower part of the back or the lungs if the patient be in bedand this tends gradually to increase till all the cavities of the body are invaded by the serous accumulation. The diseases of the lungs which produce dropsy are those which obstruct the passage of the blood through them, such as emphysema and bronchitis, and thus act precisely like disease of the heart in transferring the blood pressure from the arteries to the veins, inducing dropsy in exactly a similar manner. The diseases of the kidney which give rise to dropsy are those in which there is more or less obstruction to the secretion of the watery and saline con-stituents of the urine, accompanied by a more or less free escape of albumen ; these are the acute congestive form of nephritis following scarlet fever, the inflammatory or intratubular form of chronic Bright's disease, and the final stage of amyloid degeneration. In the two former the dropsy is often very considerable, and in the absence of cardiac disease will be found to appear first about the loose cellular tissue surrounding the eyes, where the vessels, turgid with watery blood, have less efficient support. Dropsy, though often a terminal and always a serious symptom, is yet one which much can be done to ameliorate and in many cases to remove, and this is particularly the case in many local dropsies and in those of cardiac origin. Lung, kidney, and hepatic dropsies are less amenable to treatment; yet one case of ascites is on record in which a perfect recovery took place after the woman had been tapped 133 times, and nearly 400 gallons of fluid removed. Diuretics and purgatives are the remedies chiefly employed ; but in certain cases diaphoretics and especially the use of a hot air bath are very effectual, and in a large number paracentesis or tapping is either indispensable, or at all events much expedites the cure.
It may be well to mention that there are certain affec- tions which may be termed spurious dropsies, such as ovarian dropsy, which is only a cystic disease of the ovary; hydrometria, dropsy of the uterus, due to inflammatory occlu- sion of the os uteri; hydronephrosis, dropsy of the kidney, due to obstruction of the ureter, and subsequent distention of these organs by serous accumulations; other hollow organs may also be similarly affected. (G. W. B.)