Varicose veins are twisted, swollen superficial venous blood vessels, and usually occur in the lower limbs. What are the main causes of varicose veins?Varicose veins can result from obesity and pregnancy, because the increased weight constricts the leg draining valves.They may be caused by genetic factors, such as incompetent venous valves.Varicose veins may be caused by increased build-up of blood, as a result of gravitational pressure and nonmoving legs (standing for long periods of time), as might occur in people who work as store clerks, hairdressers, and dentists, for example.All of the listed responses are correct