PLETHORA (a Greek word, waueZps, plellibre, fulness, in which sense it is used by the Greek medical writers) signifies a redundancy of blood. By the older writers the term was used to express an imagined superabundance of any of the fluids of the body ; and the terms bilious, lymphatic, and milky plethora, tic., implied the existence of an excess of one or other of those fluids in the blood. Distinctions were also made, and by a few are still retained between plethora from excess of blood, from insufficient capacity of the vessels, from deficient strength, and so on. By the majority of the physicians of the present they how ever, the term plethora is used only to express that condition in which the quantity of blood and its nutritive qualities exceed that standard which is compatible with present or the prospect of continued health.
Plethoric pereons are marked by a florid ruddy complexion, a full bard pulse, a tendency to hemorrhage from the nose or other parts, a frequent sensation of fatigue and weight in the limbs, a disposition to sleepineas, and by being in what is commonly termed good condition. In this degree plethora cannot be regarded as more than giving a tendency to tlISCRSO whenever any slight occasional cause is applied. In a greater degree however, it produces effects which are in them selves important : the complexion is yet fuller and more florid, the face seems swollen, and the eyes blood-ehot, there is pain in the head, with giddiness, ringing in the ears, dulness, heavy sleep, and a sensa tion as of flashes before the eyes, inability of exertion, constant feeling of fatigue, and frequent palpitation of the heart.
Such a condition, to which some persons seem from birth peculiarly predisposed, may be produced in nearly all by the constant use of very nutritious food, by gluttony or excess in beer, by indolence, or by the insufficiency or suppression of some habitual discharge. Its principal evil is that it renders the person who is affected by it peculiarly liable to acute inflammations and to hemorrhages in important organs, as the brain, in which the latter produce apoplexy. To avoid such con sequences, a leas nutritious diet, abstinence from exciting drinks, and the regular employment of active exercise are commonly sufficient ; but in more advanced and in extreme cases of plethora, blood must be drawn freely both from the arm and front the neighbourhood of any organ in which there seems a peculiar disposition to its accumulation, or from which It was once habitually discharged ; active aperients should also be administered, and the diet should be reduced to a much lower scale than that which had the chief share in engendering tho disorder.