The causes of visible veins are divided into physiological and pathological causes, the physiological causes are mainly due to the location of the veins, that is, the anatomical structure. Under normal circumstances, the veins are superficially located, and the veins are usually visible on the surface of the skin as cyanotic veins, but under special circumstances such as exercise and emotional excitement, hot baths, fitness, etc., the veins will be more visible to the naked eye due to the increased blood flow and expansion of the veins. Pathological causes are often the result of tortuous and dilated veins, most commonly varicose veins of the lower extremities, varicose veins of the abdominal wall, and varicose veins of the spermatic cord. For the common varicose veins of the lower extremities, blood regurgitation occurs due to the weakening of vascular elasticity and valve function after prolonged standing or sitting, and prolonged blood regurgitation increases the pressure in the veins of the lower extremities, resulting in tortuous dilatation of the veins, while tortuous dilatation in other areas, such as the thoracic and abdominal walls, is mostly due to the establishment of collateral circulation as a result of vena cava obstruction. Therefore, the causes of the veins are mainly divided into pathological and physiological. When there are unexplained tortuous dilatation of the veins, it is recommended to make a clear diagnosis under the guidance of a specialist and choose the appropriate method of treatment.