Varicose veins in the chest may be normal, or they may be caused by obstruction of the superior vena cava or obstruction of the inferior vena cava. 1. Normal phenomenon: varicose veins in the chest are mostly seen in late pregnancy or breastfeeding women, the mammary glands will be significantly enlarged by the influence of hormones in the body during this period. The blood circulation of mammary glands is more abundant, resulting in obvious varicose veins in the chest, which is a normal physiological phenomenon and does not need special treatment. 2. Superior vena cava obstruction: Varicose veins in chest may be caused by obstruction of superior vena cava. When the superior vena cava is blocked, high pressure will be formed in the superior vena cava, which will cause the superficial veins of the cervical and thoracic wall to dilate in a tortuous way and re-establish more collateral circulation, so that the blood can reach to the heart through the abdominal wall, thus slowing down the blockage of the superior vena cava, and achieving the purpose of smooth return of the blood. 3. Inferior vena cava obstruction: Inferior vena cava obstruction causes varicose veins in the abdominal wall, which can spread to the chest wall and cause varicose veins in the chest. If the patient has symptoms of varicose veins in chest, he should go to the hospital in time to do the relevant examination, and after clarifying the cause of the disease, he should be treated reasonably under the guidance of the doctor.