In addition to a physical examination, non-invasive ultrasound and plethysmography tests are often used. Heredity is the number one contributing factor causing varicose and spider veins. Women are more likely to suffer from these abnormal leg veins. Hormonal factors including puberty, pregnancy, menopause, and the use of birth control pills, estrogen, and progesterone effect the disease. It is very common for pregnant women to develop varicose veins during the first trimester.
Pregnancy causes increases in hormone levels and blood volume which in turn cause veins to enlarge.
In addition, the enlarged uterus causes increased pressure on the veins. Varicose veins due to pregnancy often improve within 3 months after delivery. However, with successive pregnancies, these abnormal veins are more likely to remain. Other predisposing factors include aging, standing occupations, obesity and leg injury. It has been an established medical specialty in Europe for 50 years, and serious interest in phlebology has developed over the last 15 years in the United States.