**5. Risk factors for CVI**

Risk factors for development of CVI include advanced age, female sex, heredity and trauma to the extremities. Lower limb injuries are a risk factor in women. Age is linked at all levels of the disease in both genders. Older age, Hispanic white ethnicity and family history are risk factors for CVI. For visible disease, CVI is about twice as common in women than in men. It was reported in the Edinburgh study that CVI was observed two-fold more in men than women [20].

Pregnancy is a critical period for the lower extremity venous system [21], and more than 30% of varicose veins develop only in this period [22, 23]. The reason is considered to be increase in the venous pressure due to the increased blood volume. Moreover, the compression of the iliac veins is an important factor in the later stages of pregnancy. Venous function is undoubtedly influenced by hormonal changes. In particular, progesterone which is released by the corpus luteum stabilizes the uterus by causing relaxation of smooth muscle fibers. This directly affects venous function. Although progesterone affects varicosities in pregnancy at first sight, estrogen also has profound effects [24].

Previous pregnancy, less oral contraceptive use, obesity and mobility at work in women, and height and straining at stool in men may be implicated in the development of reflux [25]. HRT duration or parity is positively associated with all levels of functional disease seen in women. Coughlin et al. [26] reported that multiparity was related with varicose veins in pregnant women.
