Patients develop dilated veins, often for the following reasons: i. Rapid increase of blood in the vessels: for example, pregnant women, because during pregnancy the amount of blood in the body increases by 30-40%, and as time goes on, when the pregnant woman gives birth the amount of blood decreases, and then the dilated veins become normal. Second, high local pressure: it may be caused by high local pressure, for example, severe cirrhosis can lead to dilated portal vein. Third, local thrombosis: it may be caused by local formation of thrombus, such as venous thrombosis, which needs to be clarified by ultrasound, coagulation five, angiography and so on. If this is the problem, treatment such as dilation, de-agglomeration and anticoagulation should be given, and if necessary, thrombolytic therapy or interventional thrombosis should be performed. Fourth, other causes: such as trauma or age factors, can lead to dilated veins.