Theres also a significant increase in the blood volume during pregnancy, which tends to distend veins, causing valve dysfunction which leads to blood pooling in the veins. Moreover, later in pregnancy, the enlarged uterus can compress veins, causing higher vein pressure leading to dilated veins. Varicose veins that form during pregnancy may spontaneously improve or even disappear a few months after delivery. Life-style/occupation: Those who are involved with prolonged sitting or standing in their daily activities have an increased risk of developing varicose veins. The weight of the blood continuously pressing against the closed valves causes them to fail, leading to vein distention. Other acquired causes
Acquired telangiectasia, not related to other venous abnormalities, for example on the face and trunk, can be caused by factors such as

Cushings syndrome
Rosacea
Blepharitis
Environmental damage such as that caused by sun or cold exposure
Age
Trauma to skin such as contusions or surgical incisions. Radiation exposure such as that experienced during radiotherapy for the treatment of cancer, e.g., radiation proctitis
Chemotherapy
Carcinoid syndrome
Limited systemic sclerosis/scleroderma (a scleroderma sub-type)
Chronic treatment with topical corticosteroids may lead to telangiectasia. Spider angiomas are a radial array of tiny arterioles that commonly occur in pregnant women and in patients with hepatic cirrhosis and are associated with palmar erythema. In men, they are related to high estrogen levels secondary to liver disease. Tempi syndrome
Tobacco smoking
Cutaneous collagenous vasculopathy

Treatment
Before any treatment of leg telangectasia (spider veins) is considered, it is essential to have duplex ultrasonography, the test that has replaced Doppler ultrasound.
This has ranged from display of unclothed African piebalds in "freak" shows and postcards of the early 20th century to the forcing of piebalds (as in the case of albinos) to work long hours exposed to the sun (producing high rates of lethal skin cancers), to the use of piebald humans, including children, in risky medical experiments. The National Organization of Albinism and Hypopigmentation, as well as organizations such as Under the Same Sun, work to promote awareness of all forms of cutaneous variation and their medical implications, and to highlight human rights issues, especially the plight of albinos subject to extreme persecution in parts of Africa. Etymology
The word "piebald" originates from a combination of "pie," from "magpie", and "bald", meaning "white patch" or spot. The reference is to the distinctive black-and-white plumage of the magpie. See also
References


== External links ==