Swollen feet in chemotherapy for lung cancer may be due to hypoalbuminemia, tumor metastasis, combined renal disease and so on. 1. Hypoalbuminemia: Lung cancer patients can easily consume albumin and develop hypoalbuminemia during chemotherapy. Patients with hypoalbuminemia will have decreased colloid osmotic pressure, which will lead to swollen feet, mostly seen in depressed edema. 2. Tumor metastasis: lung cancer patients are usually in the advanced stage when chemotherapy is given, and it is easy to be metastasized to the abdomen, which compresses the veins of the lower limbs, and also causes swollen feet. 3. Combination of kidney disease: With the development of disease and treatment by chemotherapy drugs, side effects will easily appear, for example, platinum-based chemotherapy drugs can easily affect kidney function, which will lead to edema of feet. If patients with lung cancer chemotherapy have swollen feet, they should clarify the specific reasons under the guidance of doctors and deal with it actively.