Some of the congenital or inherited conditions might arise due to Naevus flammeus, Klippel Trenaunay syndrome, Marfucci’s Syndrome. Hereditary hemorrhagic telangiectasia, Ataxia telangiectasia and Surge-Weber syndrome. Another cause of Spider veins is venous hypertension in varicose veins. Blood flow abnormalities can also lead to vein dilation. Factors which generally increase the cause of spider veins are – age, gender, pregnancy, menopause, obesity, long standing, exposure to ultraviolet light and occupation. The development of spider veins can occur at any age but are more frequently seen in adults. It is generally seen in people from eighteen to thirty five years of age group with less intensity and more in fifty to sixty age groups. It has been seen after research that women’s are more affected by it than men. Occupations which include long standing hours are one of the reasons of spider veins. These include the jobs of nurses, beauticians, cooks, factory men, teachers etc. When a person stands for a long duration, the skin cells near the ankle get tired and due to body weight and blood pressure, edema can result. This further leads to development of spider veins. Pregnancy is also a key factor in causing spider veins. The hormones that circulate during pregnancy in blood tend to weaken the vein walls and it also happens due to increased blood flow. Spider veins can be caused by obesity, hormonal effect during puberty or menopause, and the use of birth control pills, history of blood clots, tumors, constipation and externally worn girdles. Trauma or injury to the skin, previous vein surgeries and exposure of skin to ultraviolet rays can also lead to spider veins. Other less common causes which can lead to spider veins are Acne rosacea, environmental damage by sun’s heat or cold exposure, Carcinoid syndrome, Crest Syndrome and radiation exposure such as that experienced during radiotherapy for the treatment of cancer.