Rheumatoid Arthritis

**Semantic type:** Disease or Syndrome

**Definition:** A chronic, systemic autoimmune disorder characterized by inflammation in the synovial membranes and articular surfaces. It manifests primarily as a symmetric, erosive polyarthritis that spares the axial skeleton and is typically associated with the presence in the serum of rheumatoid factor.

**Synonyms:** - RA - Rheumatoid arthritis, unspecified - rheumatoid arthritis