Why do Thread Veins Occur?

They are thought to occur on the lower limbs in particular because of the effect on gravity blood flow, leading to pooling of blood which tends to stretch blood vessels with time. Thread veins may occur after pregnancy, because of the effect of the baby pressing on the large veins in the abdomen, which slows the flow of blood back from the legs to the heart. Occasionally thread veins may indicate a more general problem with vein circulation in the lower legs, especially if varicose veins are present, the ankles have a tendency to swell or if the skin appears abnormally dry, pigmented or inflamed. Dermatologists are very used to assessing and treating patients with these type of skin changes. The dermatologist may suggest referral to a vascular surgeon if varicose veins are present.