Editing Arthritis (section)

== Causes ==
Several factors contribute to the development of arthritis, differing on the type of arthritis.<ref name=niams/><ref name=mayo/>

Osteoarthritis occurs from damage to joint cartilage from prior injury or long-term wear-and-tear, resulting in bone-to-bone contact and grinding.<ref name=mayo/> The resulting arthritis can occur over years, or be worsened by further injury or infection.<ref name=mayo/> If joint cartilage is severely damaged, inflammation and swelling may add to the extent and pain of osteoarthritis.<ref name=mayo/>

In rheumatoid arthritis, the [[immune system]] itself, which normally serves to protect against  infection and diseases, attacks the lining of the [[joint capsule]], causing inflammation and swelling.<ref name=mayo/><ref name=niams-ra/>

[[Gout]] is a form of arthritis caused by excessive [[uric acid]] production, resulting in urate crystals depositing in joints, particularly in extremities, such as toes.<ref name="niams-gout">{{cite web|url=https://www.niams.nih.gov/health-topics/gout|title=Gout|date=December 2023|access-date=30 January 2025|publisher=National Institute of Arthritis and Musculoskeletal and Skin Diseases, US National Institutes of Health}}</ref><ref name="mayo-gout">{{cite web |title=Gout |url=https://www.mayoclinic.org/diseases-conditions/gout/symptoms-causes/syc-20372897 |publisher=Mayo Clinic |access-date=30 January 2025 |date=16 November 2022}}</ref> Urate levels in the blood may increase from consuming [[purine]]-rich foods or from body factors affecting urate clearance from the blood, a topic remaining under study.<ref name=niams-gout/>

Arthritis types may also include [[ankylosing spondylitis]], [[juvenile idiopathic arthritis]], [[psoriatic arthritis]], and [[reactive arthritis]], among others.<ref name=niams/><ref name=mayo/>