Table 1.

Differences between osteoarthritis and rheumatoid arthritis.

	Osteoarthritis	Rheumatoid Arthritis
Onset	Progressive, >40 years of age	Rapid, 20–50 years of age
Type of disease	Degenerative (wear and tear)	Autoimmune
Types of joints	Overused or weight-bearing joints, Uni- or Bilateral	Small joints of hands and feet, but may involve large joints and spine, Symmetrical/Bilateral
Morning stiffness	<20 min	>1 h
Pathophysiology	Loss of cartilage, Subchondral hypertrophy, cysts and sclerosis, Osteophytes present; Decrease of joint space	Inflammation of synovial membrane (extra-articular manifestations), Osteophytes absent, Joint destruction
Systemic symptoms	−	Anaemia, Fatigue, Weight loss, Osteopenia
Common Blood Bio-markers	Normal ESR * Normal to slightly elevated CRP ** Absence of RF Absence of ACPAs	Normal to elevated ESR * Normal to elevated CRP ** Presence or absence of RF Presence or absence of ACPAs

* Erythrocyte Sedimentation Rate; ** C-Reactive Protein.