Diagnosing Rheumatoid Arthritis

Arthritis is an autoimmune condition in which the immune system mistakenly attacks healthy tissues in your body. In rheumatoid arthritis, your immune system attacks the joints—usually the small ones in the hands and feet—causing inflammation and pain. The inflammation sometimes affects organs, such as the eyes, lungs, and heart.

Several different tissues are involved in a joint’s function. A joint is the place where two bones meet to enable movement. Each one is contained in a capsule that produces synovial fluid, which lubricates the joint, helping it to move smoothly. Cartilage, which covers the surface of a bone at a joint, serves as a cushion to ensure the bones don’t rub against each other. The muscles, tendons, and ligaments surrounding the joint provide support and control movement.

When immune system cells attack the joints, they damage the thin layer of cartilage that covers each bone on both sides of the joint. The space between the bones narrows, and eventually inflammation can cause the bones to wear down. This can cause the joint to look misshapen.

As a result, people with rheumatoid arthritis experience joint pain, stiffness, swelling, fatigue, and limited function. These symptoms occur on both sides of the body. They are usually worse upon waking, but can last all day.

Rheumatoid arthritis affects people differently. For some, joint inflammation develops slowly over the course of several years. For others, it sets in quickly. Symptoms may be mild and easily controlled, or debilitating.

People with moderate to severe rheumatoid arthritis sometimes experience symptoms in cycles. There may be a period when the arthritis seems to improve or even goes into remission, during which you have no symptoms for weeks or months. Then symptoms may return suddenly in what is known as a flare.

During a flare, people experience increased inflammation, swelling, and pain. Symptoms can last anywhere from days to months before they seem to improve. In general, with each flare-up, the arthritis tends to worsen, involving more joints and lasting longer. Ultimately, the symptoms become persistent and don’t go away unless you get treatment.

Rheumatoid arthritis affects more women than men, and it can occur at any age. It most often tends to affect women who are in their 50s. The cause is unknown, although a combination of genetics and environmental factors seems likely. Some experts believe that a bacterial infection or a virus can trigger rheumatoid arthritis in those who are genetically susceptible.

Obesity and smoking may make you more susceptible to developing rheumatoid arthritis.

Left untreated, chronic inflammation can spread to other parts of the body, such as the blood vessels and lungs. Inflammation of the sclera, the white part of the eye, can lead to pain and redness.

A person with untreated rheumatoid arthritis is also at risk of developing coronary artery disease and atherosclerosis, in which the arteries become hard and narrow. These conditions may lead to heart attack and stroke. Rheumatoid arthritis can also cause inflammation in the lungs, leading to shortness of breath.

Some people with rheumatoid arthritis are at risk of Sjogren’s syndrome. In this autoimmune disorder, the immune system attacks and damages the salivary and tear glands, causing dry mouth and dry eyes.

There is no cure for the condition, but recently developed, highly effective medications have made the disease easier to manage. They often eliminate symptoms and remove physical limitations so you can continue your usual activities.

Doctors perform several tests to diagnose rheumatoid arthritis.

Diagnostic Tests

Your doctor takes a medical history and asks when your symptoms began, whether they have worsened, and which joints are painful. Then, he or she conducts a physical exam and orders diagnostic tests.

Physical Exam

Your doctor examines your joints to see how stiff or swollen they are. He or she may also ask you to walk or bend to observe how your affected joints have altered your movements. Knowing how many joints are painful and which ones are involved can help your doctor diagnose the condition. There are several types of arthritis, and they affect joints in different ways.

Blood Tests

In autoimmune disorders like rheumatoid arthritis, the immune system produces antibodies, or proteins, to attack healthy cells. This causes chronic inflammation. So doctors draw blood and measure a person’s white blood cell count. They also check for other signs of inflammation, such as high levels of C-reactive protein—made by the liver—and low iron levels.

Our doctors also check for antibodies linked to rheumatoid arthritis, such as rheumatoid factor and anti-cyclic citrullinated peptide. These substances are present in the blood of most people with rheumatoid arthritis. Blood tests for other conditions that can mimic rheumatoid arthritis, such as hepatitis C and parvovirus, are also performed; the results should be negative if you have the condition.

A doctor can’t rely on the results of an antibody test alone to diagnose rheumatoid arthritis, because a small percentage of people who have the condition test negative for antibodies. Some people who test positive never develop rheumatoid arthritis.

Doctors ultimately diagnose the condition based on a person’s symptoms in combination with the results of blood tests. These tests should be positive for rheumatoid arthritis and negative for other conditions that can mimic rheumatoid arthritis.

X-ray

Your doctor may order an X-ray—which uses electromagnetic radiation to produce images of the body—to assess the severity of joint destruction. Although this test is not useful in the early stages of rheumatoid arthritis, it can be used to monitor the progression of the disease. X-rays are done periodically—sometimes once a year—to determine if there is worsening damage in the joints.

Ultrasound

A doctor may order an ultrasound to see if you have any active inflammation, fluid buildup, and erosion of bone. These symptoms might not be detectable on an X-ray if you have an early form of the disease.

Ultrasound is frequently more sensitive than an X-ray in detecting inflammation of the lining of the joints.

MRI Scan

A doctor may order an MRI scan to better view the joints and determine whether there is any swelling. MRI scans use a magnetic field and radio waves to create two- or three-dimensional pictures of the body.