VEINS, DISEASES OF. The physiology of the veins may be found in the article Crum:me-nos, in NAT. HIST. Div. : in the present article their principal diseases will be described. Of these the most frequent is that in which they become what is called Varicose, that is, dilated, and unnaturally tortuous, a disease which occurs especially in the subcutaneous veins of the lower extremity. It is the result of the coats of the veins losing their elasticity, and thereby their power of resisting the pressure of the column of blood above them. The loss of elasticity is commonly due to disease of their coats, and is frequently accompanied by an increase of their thickness, and by destruction or impairment of their valves. The dilated veins appear like large tortuous blue canals beneath the skin, or in extreme cases, where many are coiled together, they form projecting tumours. They pro duce inconvenience, both by the pain which results from their dis tension, and occasionally by the skin over them ulcerating, and allowing them to burst and bleed profusely ; but their more common effect is, that in parts of the skin below them, either spontaneously or after alight injuries, ulcers form, which, in consequence of the circulation being impeded through the dilated veins, are very tedious in healing.
For this varicose state of the large veins numerous remedies have been proposed ; but the best are only palliative. A temporary remedy is afforded by the recumbent posture, in which the walls of the veins are relieved from the weight of the column of blood: constant advan tage is afforded by the wearing of a well-applied bandage, or of an elastic stocking, by which a sufficient pressure is applied to prevent the further distension of the veins. The obliteration of the venous trunks may be effected by cutting or tying them in various ways, or by apply ing some caustic, so as to make the tissues over them slough ; but these proceedings are not without danger, and at present it is very doubtful whether they are often productive of permanent advantage.
Patients had better, in general, be content with the palliative remedy of the bandage or elastio stocking.
A form of varicose disease of the veins, which often accompanies that of the venous trunks, but sometimes exists alone, and with which ulcers of peculiar obstinacy occur, affects the small vessels about the ankle and lower part of the leg. The skin in this disease is almost uniformly red, through the number of small veins that are distended; the neighbourhood of the ulcer, when one exists, is livid, tense, and shining; and the ulcer itself is indolent, and very painful, and dis charges a thin sanies. This state can be treated only by the same remedies as the preceding : but, though commonly overlooked, it is by far the more mischievous disease of the two.
Varicose affection of the veins of the spermatic cord constitutes the disease named Varicocele ; and that of the veins of the rectum, or skin around it, forms hemorrhoids, or piles. In these, and in all the other cases, the blood is apt to stagnate in the dilated veins, and to co agulate within them. The clots thus formed may assume a definite form, becoming elliptical, or more often elliptical with pointed ex tremities, and the fibrin in them arranges itself in concentric layers : after this they harden, and one of their extremities becoming con nected with the walla of the vessel, small blood-vessels may form in them, and communicate with those of the surrounding parts. Lastly, the colouring-matter of the blood is removed, and earthy-matter is deposited in the clots, arranged in concentric layers, and giving them considerable hardness : thus phlebo-lithes, or vein-stones are formed. They are usually spherical, measuring from one to four lines in dia meter, lying loose within the veins, and producing no apparent inconvenience, except by obstructing the passage of blood. They are especially common in the dilated veins in the pelvis of old persons, and in the veins of legs which have bein long varicost : they neither need nor admit of surgical treatment.