A doctor may diagnose a patient with gout if he or she experiences joint swelling or pain in one to two joints, then has periods without pain. First off, in order to determine if the patient has the disease, the doctor may perform a joint fluid test, which involves collecting fluid from the joint and studying it for urate crystals. These crystals may also gather in deposits (tophi) under the skin. Blood tests can also be used but, during an acute attack of gout, uric acid concentration may appear normal or low. On the other hand, patients without gout may also have high levels of uric acid. If the patient has been living with the disease for a long time, x-rays are likely to show joint damage. Dual-energy CT scans and musculoskeletal ultrasounds can also identify urate crystals in a joint.
