Could You Have RA? How Doctors Diagnose Rheumatoid Arthritis

Here are the tests and exams doctors use to see if your achy joints are actually RA.

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You wake up in the morning and your body isn’t ready to get up and move with you. You’re stiff and achy. You’ve been noticing you’ve been more tired than usual lately, too. So you take out your computer, pull up Google, and type in your symptoms. Wait, could these really be symptoms of rheumatoid arthritis?  


What Is Rheumatoid Arthritis?

Rheumatoid arthritis (RA) is an autoimmune disease, which means the immune system—which is supposed to be your protection against viruses or bacteria—becomes active against your own tissues,” says Ashira Blazer, MD, a rheumatologist at NYU Langone Medical Center.

In RA, the immune system attacks joint tissues, causing chronic inflammation, swelling, and pain in the joints. The most commonly affected joints are knuckles, wrists, elbows, shoulders, hips, and ankles, according to Dr. Blazer.


How Doctors Diagnose Rheumatoid Arthritis

“The first question I always ask patients is, are you stiff in the morning and how long does that last,” says Dr. Blazer. Other causes of arthritis, such as osteoarthritis can cause some morning stiffness as well, but that tends to last no longer than 30 minutes, she says. “When a patient says that they’re stiff for an hour or two hours, maybe all morning long, I start to think about rheumatoid arthritis because that suggests inflammation.”

The diagnostic criteria for rheumatoid arthritis includes:

  • Pain and swelling in multiple joints and small (wrists, and certain joints of the hands and feet)
  • The same joints on both sides of the body are affected
  • Inflammatory markers in the blood
  • Morning stiffness for 30 minutes or longer
  • Symptoms last for at least six weeks

If a doctor suspects RA based on a patient’s symptoms, they may then refer them to a rheumatologist—a specialist with specific training and skills to diagnose and treat RA. To diagnose RA, the rheumatologist will then conduct a diagnostic work-up, where they’ll learn about the patient’s personal and family history, perform a physical exam, and conduct diagnostic tests.


Tests and Exams that Diagnose Rheumatoid Arthritis

“The first part of a work-up is always asking the history, making sure that the joint pain suggests that there’s inflammation,” says Dr. Blazer. “So that’s looking for some of the symptoms of stiffness, especially in the morning, looking for the symptoms of swelling, along with tenderness.”

Physical Exam

During the physical exam, the rheumatologist will examine the patient’s joints by squeezing and pressing on the joints, looking for tenderness, swelling, and painful or limited movement.

When a joint becomes inflamed, the joint capsule (synovium), becomes swollen, which impedes the joint. “It’s sort of like if you shoved a sock in the hinge of a door. So you’ve shoved this inflamed synovium in the joint, and now you can’t move the joint.”

The rheumatologist will also be looking for warmth in the joints. “[Healthy] joints should be cooler than the rest of the body, because there’s no active blood vessels going through the joint,” says Dr. Blazer. “If you’ve got inflammation there, they become very warm.”

Blood Tests

Blood tests to diagnose RA measure levels of inflammation and look for biomarkers such as antibodies (blood proteins) that are linked with RA.

Inflammation: There are two tests that measure inflammation: “The ESR, which is the sedimentation rate, and the CRP, which is the C-reactive protein. Those are proteins that are elevated when the immune system is active,” says Dr. Blazer.

A high ESR or CRP does not automatically mean a patient has RA, but when combined with other clues, like antibodies, helps make an RA diagnosis.

Antibodies: “We also look for rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP), which are antibodies that the white blood cells produce in RA,” says Dr. Blazer.

Rheumatoid factor is an antibody found in about 80 percent of people with RA. Rheumatoid factor can occur in other inflammatory diseases, so it’s not a sure sign of RA.

Anti-cyclic citrullinated peptide (anti-CCP), however, occurs primarily in patients with RA. While positive anti-CCP test gives a strong clue that it’s RA, anti-CCP antibodies are found in only 60 to 70 percent of RA patients and can exist before symptoms start.

Imaging Tests

Another important part of an RA diagnosis is getting an imaging test done, such as an X-ray, ultrasound, or magnetic resonance imaging (MRI) scan. “You can make a diagnosis based on the history, the exam, and a lot of the blood tests, so [with an X-ray] we can be pretty sure that a person has rheumatoid arthritis,” says Dr. Blazer.

“[The X-ray] tells us about the health of the bone, and it tells us whether or not RA has started damaging the bones or the joints. So we like to get the x-rays at the start, and we like to get them periodically during treatment to make sure that we’re protecting the bones by preventing inflammation,” says Dr. Blazer.

If no joint damage is found in an imaging test, that doesn’t rule out RA. It may mean that the disease is in an early stage and hasn’t damaged the joints yet.

Many patients find a lot of relief in finding out that they have RA, because the sooner you know, the sooner it can be treated. “Many patients have felt ill for some time and just want their lives back,” says Dr. Blazer. “Having the diagnosis really tells the patient, this is not you, you’re not just tired or lazy, this is an illness that’s affecting you and you’ve got to shift your life in this way.”

Diagnosed with RA? Here are tips for living with rheumatoid arthritis, according to fashion designer and RA patient Michael Kuluva.