Is It RA or Lyme Disease?

Rheumatoid arthritis (RA) and Lyme disease are very different conditions that need separate treatments. Still, they share symptoms. If you have them, you may wonder which condition you have.

What’s RA?

It's a long-term disease that leads to joint inflammation. It affects the soft tissues surrounding joints. It can also affect other organs. If you have this, your body mistakenly attacks healthy tissue.

You can get it at any point in your life. It’s most commonly found in middle age, and it affects nearly 3 times as many women as men.

Symptoms can include:

What's Lyme Disease?

Some people call Lyme disease “the great imitator,” because it can be confused with a number of other conditions, including:

Lyme disease comes from a bacterial infection that’s spread through the bite of several different kinds of ticks. It's the most common tick-borne disease in the U.S.

The disease was named for the place it was first reported in 1975 -- Old Lyme, CT. The CDC says about 300,000 people are diagnosed with it each year.

Unlike RA, it’s most common in children, older adults, and people who spend more time outdoors, like park rangers and firefighters. The more time you spend outside, the greater your chance of running into the ticks that carry the disease.

Symptoms of Lyme disease include:

The classic “bull's-eye” rash at the site of the tick bite is an excellent indicator. But the rash may not happen for everyone.

If left untreated, Lyme disease can cause health issues, including:

Get the Answer

Since the symptoms of RA and Lyme disease are so similar, it's easy to see how they might be confused. Still, it's important to find out which condition you may have.


Go to your doctor first.

To rule out RA, he’ll ask you about your symptoms and medical history. You might get a blood test to look for antibodies linked to the disease.

However, there’s no single test specifically for RA. Your doctor could send you to a rheumatologist, who’ll look over your joints for tenderness, swelling, or limited movement.

Treatment for RA includes long-term:

You may also need surgery at some point.

A blood test for Lyme can determine if an infected tick bit you. If so, antibiotics can get rid of the infection and its symptoms. It’s common to get a “false positive" early in the infection. Even if you get one, don’t delay your treatment.

There are also things called “objective findings” that can lead to a Lyme disease diagnosis. These can include:

Early treatment is key with Lyme. If you don’t get it, your symptoms may disappear for a while. But they’ll return, with more complications.

So if you suspect you have Lyme disease -- if you've been exposed to ticks or had a rash -- talk with your doctor right away.

WebMD Medical Reference Reviewed by David Zelman, MD on February 15, 2017



National Institutes of Health: “Neurological manifestations of Lyme Disease, the new Great Imitator.”

Arthritis Foundation: “What is Rheumatoid Arthritis?” “Rheumatoid Arthritis Symptoms,” “Rheumatoid Arthritis Treatment.” “About Lyme Disease,” “Lyme Disease Symptoms,” “Chronic Lyme Disease,” “Early Lyme Disease.”

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