Symptoms of RA

About one-fifth of people with rheumatoid arthritis also develop rheumatoid nodules - lumps of tissue under your skin, often over bony areas such as your elbows. The disease varies from person to person. Some people experience symptoms that come and go. These episodes are called flares and remissions. Others may have continuous symptoms that generally worsen with time.

The cause of rheumatoid arthritis is unknown and likely is due to multiple factors. Some researchers believe an infection triggers the disease among people who carry a genetic susceptibility. Researchers believe that you can't actually inherit the disease, but that you can inherit a tendency to develop it. But this hasn't been proven.

Some people with rheumatoid arthritis have a protein in their blood called rheumatoid factor. High levels of rheumatoid factor tend to be associated with more severe forms of the disease. But, not everyone who has the protein develops the disease. And not all people who have rheumatoid arthritis carry the protein.