The veins are the superficial veins on the surface of the body. The veins may be physiologic or hereditary and may be caused by pathological factors such as varicose veins caused by multiple factors. 1. Physiological factors: such as filling of veins caused by strenuous exercise or with age, subcutaneous fat becomes less and veins are gradually exposed. These are normal phenomena and do not require treatment. 2. Inborn genetic factors: some people are born with fewer elastic fibers in the vein wall, and weak elasticity will easily cause vein expansion and tortuosity, which will be manifested as vein bulging. 3. Pathological factors: Diseases such as hepatitis, cirrhosis, schistosomiasis, renal tumors, etc. cause proximal vein obstruction, which leads to obstruction of blood return and venous hypertension, which in turn leads to varicose veins, which are manifested as bulging veins. It is best to go to the hospital to find out the cause of the varicose veins, so as not to delay the condition.