The cause of disease
Weak vein wall and valve defect
The vein wall is weak and can be expanded under the action of venous pressure. The expansion of the valve sinus leads to the incomplete closure of the original venous valve, which leads to relative valve insufficiency and blood reflux. Valve dysplasia or absence can not effectively prevent reflux, leading to the disease. Venous blood itself has a certain pressure on the valve due to gravity, and it will not cause damage to it under normal circumstances. However, when the venous pressure continues to rise, the valve will gradually relax and prolapse under excessive pressure, making it incomplete. This is more common in long-term standing work, heavy physical labor, pregnancy, chronic cough, long-term constipation and so on.
Age and gender
Because the venous pressure of limbs only reaches the maximum pressure when the body length reaches the maximum, and before puberty, the body is not high and the vein diameter is small, which can prevent the vein from expanding. Therefore, although there were severe varicose veins before the age of 30, most of them gradually lost their tension with age, and the aggravation of symptoms forced patients to seek medical treatment. Varicose veins are more common in women and may be induced or aggravated by pregnancy. But in non-pregnant women, the incidence rate is also higher than that of men (male: female = 1: 3). The reason may be that the female pelvis is wide and the vascular structure is excessively curved. During menstruation, pregnancy and menopause, the veins in the pelvis will aggravate congestion. Another reason why varicose veins are prone to occur during pregnancy is that the tension of superficial veins of limbs decreases during pregnancy and it is easy to expand, which can be recovered after delivery.