Gout Diagnosis

A doctor will want to rule out other possible conditions that can cause symptoms similar to gout, such as septic arthritis and pseudogout.

To confirm or disprove a gout diagnosis, a doctor may use some or all of the following:

Physical Exam

A doctor will examine the patient’s affected joint, noting skin color, swelling, pain points, and range of motion.

The doctor will also look for the presence of bumps under the skin. These are collections of uric acid crystals (monosodium urate crystals) called tophi. Tophi are a strong indicator that a person has chronic gout.

Patient Interview

A doctor will ask a patient questions about their family medical history and the onset and pattern of their symptoms.

Joint Fluid Analysis

The most dependable way to diagnose gout is by examining the joint fluid under a microscope and looking for uric acid crystals.

To obtain a joint fluid sample, a doctor will use a needle and syringe to draw fluid from the affected joint. This procedure is called arthrocentesis or joint aspiration. The procedure may be performed using medical imaging (such as ultrasound) to ensure accurate placement of the needle. If uric acid crystals are found in the fluid sample, then a gout diagnosis is confirmed.

A small percentage of gout cases are diagnosed even though uric acid crystals are not found during joint fluid analysis.¹Neogi T, Jansen TLTA, Dalbeth N, et al. 2015 Gout classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative Annals of the Rheumatic Diseases 2015;74:1789-1798. PMCID: PMC4602275 DOI: 10.1136/annrheumdis-2015-208237 Before such a diagnosis, additional tests must be done to rule out other possibilities, such as septic arthritis (infectious arthritis).

See Diagnosis through Synovial Fluid Analysis

Blood and Urine Test

A doctor may test a blood or urine sample for uric acid levels. Abnormally high uric acid levels, called hyperuricemia, indicate gout may be present.

It is possible for the levels of uric acid in the blood to return to normal once a gout attack strikes, so the absence of hyperuricemia does not completely rule out a diagnosis of gout.

Synovial Biopsy

During a synovial biopsy, a doctor removes a small amount of tissue from the affected joint so it can be tested and examined for uric acid crystals and signs of gout. The tissue is taken from the joint’s synovial membrane, a normally thin layer of cells that surrounds the joint. A synovial biopsy is typically a minor, outpatient surgical procedure that can be done arthroscopically, so only small incisions are needed.

Ultrasound

A physician may use ultrasound to identify areas where uric acid crystals have deposited, such as in a bursa or on joint cartilage.

Dual-energy Computed Tomography

This type of medical imaging can distinguish urate crystal deposits from chemically different substances, such as calcium deposits. It may be used to identify uric acid crystals even when a joint fluid analysis does not detect them or in between gout attacks.²Sidari A, Hill E. Diagnosis and Treatment of Gout and Pseudogout for Everyday Practice. Prim Care. 2018;45(2):213-236. doi:10.1016/j.pop.2018.02.004

Dual-energy computed tomography may be referred to as dual-energy CT or DECT.

X-rays

An x-ray of the joint may show the deposition of uric acid crystals. However, x-rays can be normal even when gout is present. Experts estimate that chronic gout must be present for 5 to 10 years before joint changes can be seen on an x-ray.³Bloch C, Hermann G, Yu TF. A radiologic reevaluation of gout: a study of 2,000 patients. AJR Am J Roentgenol 1980;134(4):781–7. As cited in Sidari A, Hill E. Diagnosis and Treatment of Gout and Pseudogout for Everyday Practice. Prim Care. 2018;45(2):213-236. doi:10.1016/j.pop.2018.02.004

Most gout cases are diagnosed with a joint fluid analysis. An accurate diagnosis is important to long-term treatment and health.

During an acute gout episode, the priority is to alleviate the immediate pain and other symptoms. Once steps are taken to relieve symptoms, a treatment plan to prevent future gout attacks can begin.

Without treatment and prevention, gout can become chronic, leading to repeated episodes of intense gout pain and possibly permanent damage to the affected joint(s).