The saute condition may be produced even when no real affection of the valve exists, if the heart is so feeble that it does not contract with sufficient vigour to cause a steady and •regular circulation of the blood. The walls of the heart, yielding too much to the pressure of blood within them, may stretch unduly, and thus the heart becomes dilated and thin-walled in proportion to the degree of stretching. Under these circumstances the circulation is sluggish, and in time the blood in the veins experiences a backward pressure, which causes an undue amount of fluid to pass out into the tissues, and dropsy ensues. In these circumstances the swelling appears first in the feet and legs.
It must not, however, be thought that swell ing of the feet and legs is in every case caused by something wrong with the heart. Many people are troubled with swelling of the feet and lower parts of the legs after standing long or going about a good deal, the swelling usually disappearing after a rest in bed. This does not necessarily imply any particular disease. When a person stands, the weight of the column of blood in the veins of the legs is considerable, and if the vessels be relaxed in any degree the vessels widen unduly, and the movement of blood is slower than usual, allowing a greater oozing of fluid than can be quickly removed.
In pleurisy, dropsy of the heart, and similar instances, the accumulation of fluid is due not to obstruction to the return of fluid, but to an active determination of a much greater than ordinary quantity of blood by the acute inflam mation going on.
The treatment of dropsy depends on the cause.
In cases where the dropsical effusion is due to an inflammatory process, the treatment of the dropsy is bound up with the treatment of the inflammation. Sometimes, however, the effusion is so great, as it may be in pleuritic effusion and dropsy of the heart, as to cause grave embarrassment, which cannot, without risk, be permitted to continue. In such cases
some, if not all, of the fluid may be removed by tapping or aspiration.
In cases where the cause is not an active in flammation but some retardation of the onward flow, the organ responsible must be discovered; the state of the liver should be corrected if possible, the weak heart strengthened, &c.
Drugs are employed for the purpose of re moving from the blood and casting out of the body a larger amount of water than usual, and so encouraging the picking up of the dropsical fluid into the current of the circulation. Active purgatives, which cause large evacuations of watery stools, do this, such as jalap and ela terium. Other drugs effect the same thing by promoting an increased flow of urine, such as nitre, gin, spirits of juniper, and digitalis. Pro fuse sweating by means of hot-air baths aids in a similar way. Digitalis is a very useful drug, since it both strengthens the heart and pro motes the action of the kidneys. It is in cases where the dropsy is due to some condition of the heart that digitalis proves most valuable. By its strengthening action on the heart it causes inure vigorous contractions and tends to restore efficiency to the circulation. But the employment of these means is always attended with risk, unless used by those who really understand the cause of the dropsy and adapt the remedy with care to the circumstances of the case. Therefore the treatment needs deter mination by a physician.
In cases of dropsy depending on kidney dis ease, the avoidance of salt, both in the cooking and eating of food, and the use of foods in the constitution of which salt is in small quantity, produces frequently excellent results.