What is Osteoarthritis?

Arthritis is a joint disorder characterized by swelling.  A joint is an area of the body where two different bones meet. Joints are found in the knees, hips, fingers and other areas of the body that bend to ease movement. There are many types of arthritis, one of which is called osteoarthritis.

Osteoarthritis is the most common joint disorder in the world1. In Western populations, radiographic (X-ray) evidence of osteoarthritis can be found in the majority of people at 65 years of age, and in about 80% of those aged over 75 years1.

In osteoarthritis, there is a breakdown of the substance (cartilage) that provides a cushion between the bones that meet at the joint.  This breakdown leads to the pain and swelling that occurs when the bones begin to rub against one another2.

Osteoarthritis occurs more frequently as we age, and more commonly affects the:

  • Knee
  • Hip
  • Hand
  • Spine 
  • Foot

Unlike other forms of arthritis, osteoarthritis does not affect other organs of the body.  Symptoms are limited to the joints themselves and manifest most commonly as pain and swelling with repetitive use, with pain usually being worse later in the day. Along with pain and swelling there may be warmth, morning stiffness and creaking of the affected joint3,4.


1. Arden N, Cooper C (2006) Osteoarthritis: epidemiology.  In:  Arden N, Cooper C (eds) Osteoarthritis Handbook, Taylor & Francis, London,  pp 1-22
2. Nevitt  M, (2006) Risk factors for knee, hip and hand osteoarthritis.  In: Arden N, Cooper C (eds) Osteoarthritis Handbook, Taylor & Francis, London, pp 23-48
3. Klippel JH, Stone JH, Crofford L, White PH, (2008) Primer on the Rheumatic Diseases, 13th edn. Springer and Arthritis Foundation, New York
4. Creamer P, (2006) Management of Osteoarthritis. In: Arden N, Cooper C (eds) Osteoarthritis Handbook, Taylor & Francis, London, pp 185-204