RA, or rheumatoid arthritis, is a chronic autoimmune disease in which the immune system mistakenly attacks the lining of your joints, causing pain, swelling, and progressive damage. It affects roughly 0.5 to 1% of the global population, strikes women two to three times more often than men, and can appear at any age, though it peaks around 60.
Unlike osteoarthritis, which results from physical wear and tear on cartilage, RA is driven by immune system dysfunction. That distinction matters because it changes everything about how the disease behaves, what it does to the body, and how it’s treated.
What Happens Inside the Joint
Every joint is lined by a thin tissue called the synovial membrane. In RA, immune cells flood into this membrane and release inflammatory signals that keep the attack going. White blood cells, including types that normally fight infections, accumulate in the joint space and interact with the cells that line it. The result is a self-sustaining cycle of inflammation called chronic synovitis.
One key driver involves antibodies that target altered proteins in the joint. These antibodies ramp up production of a powerful inflammatory molecule called TNF-alpha, which prevents the inflammation from resolving on its own. Over time, this persistent inflammation reshapes the joint itself. Bone-building cells decrease while bone-destroying cells increase. Cartilage degenerates. Bone erosions form at the points where the synovial membrane attaches to bone. Without treatment, this process can permanently deform the joint.
Early Symptoms to Recognize
The hallmark of RA is morning stiffness lasting 60 minutes or longer. Most people with osteoarthritis feel stiff for a few minutes after waking; in RA, that stiffness can persist for hours. It typically improves with movement throughout the day.
RA tends to affect joints symmetrically. If the knuckles on your left hand are swollen and tender, the same knuckles on the right hand usually are too. The small joints of the hands, wrists, and the balls of the feet are the most common early targets. Affected joints often feel warm to the touch and visibly swollen, not just sore. Fatigue is another early and persistent feature that many people underestimate.
Osteoarthritis, by contrast, tends to affect weight-bearing joints like knees and hips, often on one side more than the other, and inflammation markers in blood work are usually normal or only mildly elevated. In RA, blood markers of inflammation are frequently significantly elevated.
How RA Is Diagnosed
There’s no single test that confirms RA. Rheumatologists use a scoring system developed by the American College of Rheumatology and the European League Against Rheumatism that adds up points across four categories: the number and type of joints involved, blood test results, inflammation levels, and how long symptoms have lasted. A score of 6 out of 10 or higher, combined with confirmed joint swelling that can’t be explained by another condition, leads to a formal classification of RA.
Two blood tests are central to the workup. Rheumatoid factor (RF) is positive in many RA patients but also shows up in other conditions, giving it a specificity of about 85%. The anti-CCP antibody test is more telling: it has a specificity of 95%, meaning a positive result is a strong signal that RA, specifically, is the cause. Both tests have similar sensitivity (around 67 to 69%), so a negative result doesn’t rule RA out. Some people have what’s called seronegative RA, where both tests come back negative but the clinical picture still points clearly to the disease.
Doctors also check markers of general inflammation, such as C-reactive protein and the erythrocyte sedimentation rate. Imaging of the hands, wrists, and feet can reveal early erosions or swelling that isn’t obvious on a physical exam. The scoring system assigns the most weight to how many joints are involved: having more than 10 affected joints, with at least one small joint, earns the maximum 5 points on its own.
Effects Beyond the Joints
RA is a systemic disease, meaning it doesn’t stay confined to the joints. About 20% of people with RA develop rheumatoid nodules, firm lumps that form under the skin, most commonly on the forearms and elbows. These occur almost exclusively in people who test positive for rheumatoid factor. Less commonly, nodules can form in the lungs or heart.
The cardiovascular risk is significant. Women with RA have twice the risk of heart attack compared to women without it, and after 10 years of disease, that risk triples. The chronic inflammation that drives joint damage also stiffens and thickens artery walls, accelerating atherosclerosis. This makes managing cardiovascular risk factors like blood pressure and cholesterol especially important for people living with RA.
Lung involvement is another concern. Interstitial lung disease, a condition where scarring develops in lung tissue, is associated with RA and tends to appear more often in men with long-standing disease who are rheumatoid factor positive.
Treatment and Remission
The goal of modern RA treatment is remission, not just symptom management, and early treatment dramatically improves the odds. When treatment begins early with disease-modifying medications, remission rates can exceed 60%.
The first line of treatment is a class of drugs called conventional DMARDs (disease-modifying antirheumatic drugs). These are oral medications that suppress the overactive immune response broadly. Methotrexate is the most widely used and typically the first one prescribed. It’s cost-effective, well-studied, and remains the backbone of RA treatment for most people.
When conventional DMARDs aren’t enough, biologic DMARDs are the next step. These are protein-based medications, usually given by injection or infusion, that block specific inflammatory molecules. Some target TNF-alpha, the key inflammatory signal in RA. Others block different immune pathways involving specific types of white blood cells or inflammatory proteins like interleukin-6. A newer option, targeted synthetic DMARDs, are oral medications that interrupt inflammatory signaling inside cells. These work through a different mechanism than biologics but serve a similar role for people who haven’t responded to earlier treatments.
Treatment strategy in RA follows a “treat to target” approach. Your rheumatologist sets a specific goal, usually remission or very low disease activity, checks your progress at regular intervals, and adjusts medications if you’re not reaching that target. This structured approach is what drives those high remission rates.
Diet and Lifestyle Factors
A Mediterranean dietary pattern, rich in fish, vegetables, olive oil, and low in red meat and dairy, has drawn the most research attention for RA. The rationale is straightforward: fatty fish is rich in omega-3 fatty acids, which have well-documented anti-inflammatory effects. Fish oil supplementation specifically has been studied extensively in RA and shows benefits for joint tenderness and stiffness.
That said, diet alone doesn’t replace medication. Studies examining the effect of anti-inflammatory diets on objective inflammation markers like C-reactive protein in RA patients have shown modest or inconsistent results. The practical takeaway is that a Mediterranean-style diet is a reasonable complement to medical treatment, not a substitute for it. Regular physical activity, particularly low-impact exercise like swimming, cycling, or walking, helps maintain joint mobility, reduces fatigue, and supports cardiovascular health, which is especially relevant given the elevated heart disease risk in RA.