What Is Rheumatoid Arthritis? Symptoms, Causes, Diagnosis, Treatment, And Prevention

illustration of joint pain related to rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease of the joints. Within the body, joints are the points where bones come together and allow for movement. Most of these joints — those called synovial joints — also provide shock absorption.

RA is an autoimmune condition, in which your immune system mistakes the linings of your joints as “foreign” and attacks and damages them, resulting in inflammation and pain.

This disease most often affects the joints of the hands, wrists, and knees symmetrically. There is no cure, but RA can be managed with good treatment, according to the Centers for Disease Control and Prevention (CDC).

Signs and Symptoms of Rheumatoid Arthritis

Rheumatoid arthritis is a complex disease that is not well understood by medical practitioners or researchers.

Early signs of disease, such as joint swelling, joint pain, and joint stiffness, typically begin in a gradual and subtle way, with symptoms slowly developing over a period of weeks to months and getting worse over time. RA usually begins in the small bones of the hands (particularly those at the base and middle of the fingers), base of the toes, and wrists. Morning stiffness that lasts for 30 minutes or more is another hallmark symptom of RA, per the Arthritis Foundation.

RA is a progressive disease. When left untreated, inflammation can start to develop in other parts of the body, causing various potentially serious complications that can affect other organs, such as the heart, lungs, and nerves, and could cause significant long-term disability.

If you’re experiencing RA symptoms, it’s crucial to get diagnosed as soon as possible so that you can receive prompt treatment.

Causes and Risk Factors of Rheumatoid Arthritis

RA develops when white blood cells, which normally protect the body from foreign invaders such as bacteria and viruses, enter the synovium (the thin tissue that lines the synovial joints). Inflammation ensues — the synovium thickens, causing swelling, redness, warmth, and pain in the synovial joint.

Over time, the inflamed synovium can damage the cartilage and bone within the joint, as well as weaken supportive muscles, ligaments, and tendons.

Researchers don’t know exactly what causes the immune system to invade the synovium, but it’s believed that genes and environmental factors play a role in the development of RA.

Research suggests that people with certain genetics, namely the human leukocyte antigen (HLA) genes, have a significantly increased risk of developing RA.

The HLA gene complex controls immune responses by producing proteins that help the immune system recognize proteins from foreign invaders.

A number of other genes also appear to be associated with RA susceptibility, including STAT4, PTPN22, TRAF1-C5, PADI4, CTLA4, among others, according to a report in the journal Rheumatology.

But not everyone with these identified gene variants develops RA, and people without them can still develop it. So, it’s likely that environmental factors often trigger the disease, particularly in people with a genetic makeup that makes them more susceptible to it. These factors include:

Viruses and bacteria (though certain infections may reduce RA risk, at least temporarily)
Female hormones
Exposure to certain kinds of dust and fibers
Exposure to secondhand smoke
Obesity, which also increases progression of disability for people with RA.
Obese patients are less likely to achieve RA remission regardless of the treatment they receive.
Severely stressful events
Foods

Equally important are smoking and a family history of RA in increasing a person’s risk of developing the condition.

Children up to age 16 who experience prolonged swollen or painful joints anywhere in the body are typically diagnosed with juvenile idiopathic arthritis (JIA).

How Is Rheumatoid Arthritis Diagnosed?

While no single test can definitively diagnose RA, doctors consider several factors when evaluating a person for rheumatoid arthritis.

The diagnostic process typically begins when a doctor gets your medical history and conducts a physical exam. They will ask you about your symptoms to look for signs of RA, in particular things like prolonged joint swelling and morning stiffness that lasts at least half an hour after you wake up.

Next, your doctor will order blood tests to detect rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs), which can be specific markers for RA and could indicate RA. You can still have symmetrical inflammatory arthritis with or without systemic markers of inflammation.

Imaging tests such as X-ray, ultrasound, and magnetic resonance imagery scans may be used to help a doctor determine if your joints have been damaged or to detect joint inflammation, erosion, and fluid buildup.

In the future, doctors may be able to diagnose RA using (noninvasive) infrared light.

The Different Types of Rheumatoid Arthritis

Rheumatoid arthritis is classified as either seropositive or seronegative.

People with seropositive RA have ACPAs, also called anti-cyclic citrullinated peptides, found in their blood test. These antibodies attack the synovial joints and produce symptoms of RA.

About 60 to 80 percent of people diagnosed with RA have ACPAs, and for many people, the antibodies precede the symptoms of RA by 5 to 10 years, notes the Arthritis Foundation.

People with seronegative RA have the disease without the presence of the antibodies or RF in their blood.