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Swelling is not specific to kidney disease. Heart problems, liver disease, problems with leg veins, certain medications and several other medical conditions can also cause edema. Even prolonged sitting can cause temporary ankle swelling in some people. New, persistent or rapidly worsening swelling deserves medical evaluation rather than assumptions about its cause. Sudden swelling accompanied by difficulty breathing can be particularly concerning and may require urgent medical attention.
Changes in urination are another reason people sometimes seek kidney evaluation. Chronic kidney disease can be associated with urinating more frequently or less frequently than usual, and some people notice an increased need to urinate at night. Other kidney or urinary tract conditions may cause discomfort, changes in urine appearance or blood in the urine. Because the kidneys produce urine, changes in kidney function can sometimes alter urinary patterns. However, many people with kidney disease continue producing apparently normal amounts of urine, especially in earlier stages.
Foamy urine can sometimes indicate protein in the urine. Occasional bubbles can occur normally because of the force of urination or substances in the toilet water. Persistent or unusually foamy urine, particularly when it repeatedly appears despite flushing, can sometimes be associated with proteinuria. Proteinuria means that more protein than expected is passing through the kidneys into the urine. A laboratory urine test is required to determine whether excess protein is actually present.
Visible blood in urine should also be medically evaluated. Blood can make urine appear pink, red, brown or cola-colored, although some causes produce blood that can only be detected under a microscope. Kidney disease is one possible explanation, but urinary tract infections, kidney stones, prostate conditions and other disorders can also cause bleeding. Certain foods and medications can even change urine color without blood being present. Because the possibilities range from minor to serious, visible blood in urine should not simply be attributed to kidney disease without testing.