How is gout in the knee diagnosed? My uric acid test was normal.

Joint fluid: the key test

A thin needle is used to draw a small amount of fluid from the knee, usually in a few minutes in clinic. The sample is examined under a polarising microscope for crystals and sent for cell count and culture to exclude infection.

This is the only test that both confirms gout and separates it from pseudogout and infection, which is why it is recommended for a first episode or when the picture is unclear. Draining the fluid often eases the pain too.

Why the blood test can mislead

Uric acid in the blood can temporarily drop during an attack, so a normal reading at that time does not exclude gout. Equally, many people have a high uric acid level and never get gout. The test is more useful two to four weeks after the flare has settled, and for monitoring treatment.

Other blood tests usually include inflammation markers, kidney function, blood sugar and cholesterol, because gout is linked with kidney disease, diabetes and heart risk.

Imaging that helps

• X-ray: often normal early on; later it may show erosions from gout or calcium lines that point to pseudogout, and it shows any osteoarthritis
• Ultrasound: can show a typical coating of urate on the cartilage surface and guide the needle into the joint
• Dual-energy CT: a specialised scan that can map urate deposits when the diagnosis remains uncertain
• MRI: not routinely needed, but useful if another problem such as a meniscus tear or bone injury is suspected

Having it checked in Doha

Bring a list of your medicines, any previous blood results and a note of how often the knee has flared. At Aman Hospital Dr. Gelber takes the history, examines the knee, performs aspiration when it is needed and arranges imaging. If gout is confirmed, he will explain the treatment plan and liaise with your GP or a rheumatologist for long-term care.