Patients with bad kidney can have swelling and pain in their feet. The usual term bad kidney refers to chronic glomerulonephritis, chronic renal failure and other diseases, and patients with these diseases can all have foot symptoms. Patients with kidney disease have swollen feet due to protein loss and decreased plasma osmolarity, resulting in water and sodium retention. Patients with renal insufficiency have swollen feet because they cannot excrete excess water due to low or no urine volume. In addition, patients with chronic renal failure have poor uric acid excretion and will have symptoms of elevated uric acid, which can cause pain in the feet in severe cases, caused by high uric acid, at which time you can take drugs such as febuxostat to reduce uric acid.