The hallmark symptom of rheumatoid arthritis is morning stiffness that lasts for at least an hour. (Stiffness from osteoarthritis, for instance, usually clears up within half an hour.) Even after remaining motionless for a few moments, the body can stiffen; movement becomes easier again after loosening up. Symptoms such as fatigue, weight loss, and fever may accompany early rheumatoid arthritis. Some people describe them as being similar to those of a cold or flu, except, of course, RA symptoms can last for years. Swelling and pain in the joints must occur for at last six weeks before a diagnosis of rheumatoid arthritis is considered. Although rheumatoid arthritis almost always develops in the wrists and knuckles, the knees and joints of the ball of the foot are often affected as well. Indeed, many joints may be involved. The pain often occurs symmetrically but may be more severe on one side of the body, depending on which hand the person uses more often. It does not usually show up in the finger tips, where osteoarthritis is common, but joints at the base of the fingers are often painful. The inflamed joints are usually swollen and often feel warm and "boggy" when touched.

In about 20% of people with RA, inflammation of small blood vessels can cause nodules, or lumps, under the skin. They are about the size of a pea or slightly larger, and are often located near the elbow, although they can show up anywhere. Nodules can occur throughout the course of the disease; they are usually painless, but rarely they can reflect the presence of rheumatoid vasculitis, a condition that can affect blood vessels in the lungs, kidneys, or other organs. Rarely, nodules may become sore and infected, particularly if they are in locations where stress occurs, such as ankles.

Fluid may accumulate, particularly in the ankles. In rare cases, the joint sac behind the knee accumulates fluid and forms what is known as a Baker cyst; it feels like a tumor and sometimes extends down the back of the calf causing pain.

In children, juvenile rheumatoid arthritis, also known as Still's disease, is usually preceded by high fever and shaking chills along with pain and swelling in many joints. A pink skin rash may be present and internal organs, such as the lungs and heart, may be involved.