The only certain way to diagnose gout is to have a joint fluid aspiration (arthrocentesis) test to see whether uric acid crystals are present. However, in people with an acutely swollen, red, painful big toe, where it is often difficult to obtain joint fluid, a diagnosis can be made by the presence of a high blood uric acid level.

The following examinations and tests may help with diagnosis and treatment of gout:

• Medical history and physical examination
• Test to measure levels of uric acid in blood
• Test to measure levels of uric acid in urine

While X-rays of extremities (hands and feet) are sometimes useful in the late stages of the disease, X-rays are not usually helpful in the early diagnosis of gout. When gout is in a late stage, nodules (tophi) or even "punched-out" (worn away or eroded) areas of bone near joints may be seen.⁶ The pain of gout often causes people to seek medical attention before any long-term changes can be seen on an X-ray. However, X-rays may help to rule out other causes of arthritis. See an X-ray of gout in the foot.