Foot swelling caused by multiple myeloma in advanced stage may be caused by nephrogenic edema, cardiogenic edema, hypoproteinemia, etc. It is usually more dangerous and needs active treatment. 1. Nephrogenic edema: multiple myeloma can produce a large amount of light chain protein, which will lead to renal tubular damage and even trigger renal insufficiency. When renal dysfunction occurs, patients may have the symptom of double lower extremity edema, at this time, it is necessary to actively protect renal function, otherwise it may increase the degree of renal injury. 2. Cardiogenic edema: multiple myeloma may also cause myocardial amyloidosis, and when the cardiac function is affected, the patients also have lower limb edema, and cardiac insufficiency has a greater impact on the patients, which needs to be actively dealt with. 3. Hypoproteinemia: patients with multiple myeloma may have hypoproteinemia due to the consumption of the disease, and hypoproteinemia will also lead to the manifestation of generalized edema. This condition is less dangerous than renal insufficiency and cardiac insufficiency, but still needs active management. Swollen feet in advanced stages of multiple myeloma need to be taken seriously and actively consulted and treated to avoid aggravation of the condition.