How is it different from arthritis?

Arthritis and related diseases can cause debilitating, life-changing pain. According to the Centers for Disease Control and Prevention, more than one-third of the adults who have arthritis report that it limits their leisure activities and work. And 25 percent of them say it causes severe pain (seven or higher on a zero to 10 point scale).

There are more than 100 different forms of arthritis and related diseases. The most common types include osteoarthritis (OA), rheumatoid arthritis (RA), psoriatic arthritis (PsA), fibromyalgia and gout. All of them cause pain in different ways.

Osteoarthritis
In osteoarthritis (OA), the protective cartilage inside the joint breaks down. This makes movement of affected joints more difficult and painful. In time, bones of the joint may rub directly against one another, causing severe pain. Pain can also come from parts of your joint other than the cartilage, such as bone, synovium and ligaments. The intensity of OA pain varies from person to person and can range from mild to severe. You can read more about sources of OA pain and pain treatments in our Breaking the Arthritis Pain Chain toolkit.

Rheumatoid Arthritis
In rheumatoid arthritis (RA), the joints and other organs are attacked by the body’s own immune system. The immune system normally protects a person from viruses, bacteria and other invaders. In people with autoimmune diseases like RA, it becomes overactive and attacks healthy tissue. In the case of RA, the immune system primarily goes after the lining of the joints, called the synovium. Over time, the persistent inflammation breaks down the joint and damages it permanently.

Pain in RA can come from other parts of your joint besides the synovium, such as bone and ligaments. You can read more about sources of inflammatory pain and its treatments in Breaking the Arthritis Pain Chain toolkit.

Psoriatic Arthritis
Psoriatic arthritis (PsA) is an autoimmune inflammatory disease in which the immune system attacks the body, causing inflammation and pain. PsA affects the joints, causing arthritis; the connective tissue where tendons or ligaments attach to bones, causing enthesitis; and the skin, causing psoriasis. You can read more about sources of inflammatory pain and its treatments in Breaking the Arthritis Pain Chain toolkit.