Leg swelling after chemotherapy may be due to cardiac insufficiency, or it may be due to hypoproteinemia or massive hydration. 1. cardiac insufficiency: chemotherapeutic drugs have a certain degree of cardiotoxicity, such as antitumor drugs, repeated use will cause some damage to the patient’s heart, so that their cardiac function is reduced, so there may be body circulation disorders, which is manifested in the limbs of the blood vessels bruising, edema. 2. Hypoproteinemia: many toxic side effects will occur after chemotherapy, the more common is the gastrointestinal reaction, which will lead to insufficient nutritional supplementation, reduced blood albumin concentration, plasma colloid osmolality decreased, and edema. 3. Large amount of hydration: some chemotherapy drugs require large amount of hydration to reduce renal toxicity. Large amounts of hydration may cause lower extremity edema if it is not excreted in a timely manner. If swelling occurs after chemotherapy, it is recommended to communicate with the doctor to clarify the cause and follow the doctor’s instructions for symptomatic intervention.