You’ve had episodes of pain and swelling in your feet, ankles and knees for some time and your doctor tells you that you have rheumatoid arthritis. Despite treatment, you develop excruciating pain in your big toe, and you continue to have attacks of pain and swelling in your joints. What is going on?

According to the Arthritis Foundation, you may not have RA at all. You may have gouty arthritis — or gout — instead.

Gout and RA share many characteristics. Both diseases are chronic, incurable inflammatory conditions. Both can cause redness and swelling in the joints, and both can eventually lead to joint destruction and damage to the cartilage and ligaments in the joints, as well as damage to major organs in the body. Both RA and gout are also subject to periods of remission and symptom flares.

Can you have both RA and gout?

Yes, but for the most part, it’s rare. “There is a relatively small number of people who have both conditions,” says Dr. Theodore R. Fields, a rheumatologist at the Hospital for Special Surgery in New York.

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Rheumatoid arthritis is an autoimmune disorder in which the body’s immune system mistakenly attacks and damages healthy tissue. Gout occurs when excess uric acid, a bodily waste byproduct, is deposited as crystals of sodium urate in some joints.

Gout can develop for a number of reasons. Genetic factors can trigger gout, or kidney disease can impair the body’s ability to eliminate uric acid from the blood, causing it to build up.

Drugs like diuretics and low-dose aspirin can also cause an accumulation of uric acid, as can alcohol and foods rich in purines, compounds that are broken down into uric acid. Purine-rich foods include wild game; organ meats like kidney or liver; red and dark meat; seafood like herring, scallops, mussels, cod and haddock; beer; gravy; and high-fat dairy products.

Gout occurs more frequently in overweight people and men, though it becomes more common in women following menopause.

In its later and chronic stages, gout can closely resemble RA, causing pain and inflammation in multiple joints. If not treated properly, it can also be associated with positive rheumatoid factor, an antibody that is found in the blood of many people with RA.

Sodium urate crystals can also cause lumps to form under the skin, similar to rheumatoid nodules, which can develop in people with RA.

Despite these similarities between RA and gouty arthritis, there are several differences.

Gout typically begins with extreme pain and swelling in the big toe that often begins after an illness or injury. Attacks usually occur off and on, and can eventually progress to other joints, especially the joints of the feet and knees. After a few years, gout can become chronic and affect the joints of the hands.

In contrast, RA usually involves pain, swelling, redness, tenderness and heat felt in multiple joints at once, and typically begins in the fingers, wrists and toes. The symptoms often occur gradually, and they are usually symmetric — involving the same joints on both sides of the body.

Both RA and gout require drug therapy, but the medications used to treat them are different.

Information from the Mayo Clinic says people with RA are prescribed a regimen that can include disease-modifying anti-rheumatic drugs like methotrexate, and biologics, drugs that modify the body’s immune response, like etanercept (Enbrel), adalimumab (Humira), abatacept (Orencia) and others. Corticosteroids can also be prescribed, especially during flares of the disease.

Medications for gout include drugs called xanthine oxidase inhibitors to decrease uric acid levels in the blood, including allopurinol (Aloprim, Lopurin and Zyloprim) and febuxostat (Uloric). Other drugs are prescribed to relieve gout’s pain and inflammation, including nonsteroidal anti-inflammatory drugs like ibuprofen, and colchicine, which specifically targets gout’s pain. Corticosteroids may also be prescribed to alleviate pain and inflammation.

These drugs are generally very effective in treating the disease. However, there are obstacles in treating gout. The first of these is misdiagnosis. If your doctor mistakenly diagnoses you with RA or another condition, he or she cannot properly treat gout.

In other cases, people with gout fail to follow a proper diet or limit their consumption of alcohol, or they do not take their medication as prescribed.

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When gout is not well-controlled, the consequences can be serious. A recent study reported in the Journal of the American Medical Association found that hospitalizations for gout in the U.S. increased between 1993 and 2011. In contrast, during the same period, hospitalizations for RA decreased.

“The improvement in the RA patients was likely due to fewer joint replacements and to better medical therapies,” says Fields, who is also a professor of clinical medicine at Weill Cornell Medical College in New York.

The study examined whether the increased rate of hospitalization for people with gout was because they did not receive optimal care.

“[This] is supported by numerous articles that show that gout patients are not reaching their ‘goal’ — which is to get their uric acid [levels] below 6,” Fields explains. Normal values vary for males and females, but range from 3.5 to 7.2 mg/dL. To achieve this goal, “gout patients generally need medication, such as allopurinol, which lowers the uric acid.”

Fields further explains that diet alone cannot typically lower uric acid levels enough, and medication needs to be monitored to ensure optimal disease control.

“For allopurinol to get the gout patients to their goal, the dose often needs to be adjusted, or changed to another medication, or supplemented by another medication,” Fields says. “To make adjustments, uric acid levels need to be followed.”

Many people with gout do not have their uric acid levels measured, even if they are taking medication, Fields says. “Thus [they have] never reached their goal.”

The other finding of this study is that the rates of RA have remained relatively stable, while the incidence of gout has been increasing.

“The worsening hospitalization rate with gout, therefore, may be due to a combination of increased frequency of the condition and suboptimal care,” Fields says.

The first step in maximizing treatment is to make certain you have the correct diagnosis. “Numerous disorders may masquerade as RA,” says Dr. John J. Cush, a rheumatologist and the director of clinical rheumatology for the Baylor Research Institute in Dallas.

Gout is one of these conditions.

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If you have been diagnosed with RA and drug treatment is not working, keep track of all your symptoms. Tell your physician if your joint pain and swelling only occur from time to time, and whether your symptoms are symmetric — on both sides of the body — or involve only one side.

In addition, ask your rheumatologist to take a sample of the fluid in your joints and examine it for the presence of urate crystals, which are a hallmark of gout.

Whether you have RA or gout, or if you’re one of the rare people who have both, it’s essential to get the correct diagnosis so you can be treated properly, which will increase the chances of controlling your disease and limiting future joint and organ damage.

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Could You Have Gout Instead of Rheumatoid Arthritis? originally appeared on usnews.com