Your GP may suspect gout based on your symptoms. Sometimes further tests will be needed to confirm the diagnosis and rule out other possible causes.
Seeing your GP
See your GP if you experience symptoms of gout for the first time. Your GP will ask about your symptoms and medical history, and examine the affected area, to help make a diagnosis. They may also ask you about your diet, particularly your intake of beer, spirits and foods high in purines, such as red meat and seafood.
Many conditions can cause gout-like symptoms. Your GP may be unable to make a firm diagnosis straight away and you may be referred for further tests. These will either confirm the diagnosis of gout or rule out other conditions.
Joint fluid test
A sample of fluid may be taken from the affected joint. The fluid can be checked for the small crystals that cause gout, and it can be tested for infection to rule out septic arthritis.
A blood test known as a serum uric acid test may be used to measure the amount of uric acid in your blood. A high level or uric acid is often associated with gout. It’s sometimes best to wait until two to four weeks after an attack of gout before this test is carried out, as the level of uric acid in your blood is often not raised at the time of an attack. This is because the level of uric acid in your blood can drop when uric acid crystals form in the joints.
An X-ray is rarely used to diagnose gout because the condition isn’t usually detectable using this method. However, an X-ray is sometimes used to help rule out similar conditions that affect the joints, such as chondrocalcinosis (a build-up of calcium crystals in the joints) or to assess whether there has been any joint damage due to repeated or persistent attacks of gout.
An ultrasound scan of an affected joint is a simple and safe investigation that’s increasingly used to detect crystals in the joints. It can also detect crystals deep in the skin that aren’t obvious during a physical examination.
Source: NHS UK