Is It RA or Lyme Disease?

Medically Reviewed by David Zelman, MD on December 06, 2022
3 min read

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.

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:


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. About 30,000 cases are reported each year, but the CDC believes the number is 10 times higher than that.

Unlike RA, Lyme is 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:


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

Your doctor may 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 if the diagnosis is quick. If you don't have the telltale rash, it may take a few weeks for antibodies to show up on a blood test..

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.