INTRODUCTION
Arthritis is a term used to describe a number of painful conditions of the joints and bones. Two of the main types of arthritis are osteoarthritis and rheumatoid arthritis.
Osteoarthritis: Osteoarthritis is the most common form of arthritis. Cartilage (connective tissue) between the bones gradually wastes away (degenerates), and this can lead to painful rubbing of bone on bone in the joints. It may also cause joints to fall out of their natural positions (misalignment). The most frequently affected joints are in the hands, spine, knees and hips.
Rheumatoid arthritis: Also known as inflammatory arthritis, rheumatoid arthritis is a more severe, but less common condition. The body's immune system attacks and destroys the joint, causing pain and swelling. It can lead to reduction of movement, and the breakdown of bone and cartilage.

SYMPTOMS
The main symptoms of all forms of arthritis include stiffness, pain, restricted movements of the joints,
swelling and warmth and redness of the skin over the joint.

Osteoarthritis: Osteoarthritis often develops in people who are between 40-60 years of age. Osteoarthritis becomes more common with age with around 12% of people over 65 affected by the condition. Osteoarthritis begins slowly with pain, stiffness and restricted movement in the affected joints. For some, slight stiffness is all that is experienced, but other people go on to have cracking or creaking joints (crepitation), knobbly bone growths (especially on the hands), and joints that move out of alignment. The pain and loss of movement tends to worsen as the day goes on, as the joints are used more.
Rheumatoid arthritis: Rheumatoid arthritis affects between 1-3% of the population, and often starts between 30-50 years of age. Women are three times more likely to be affected by rheumatoid arthritis than men. Like osteoarthritis, rheumatoid arthritis begins gradually, with the first symptoms often being felt in small joints, such as fingers or toes. The condition can then progress to cause pain, swelling and stiffness of other joints, causing a lack of mobility. Cold and damp weather may aggravate the symptoms which are often worse in the morning. However, your symptoms may improve during the day as you start using and flexing your joints. Rheumatoid arthritis can also sometimes leave people feeling generally unwell and tired.

CAUSES
The cause of osteoarthritis is not fully known. One theory is that some people are genetically predisposed to developing the disease, but this has not yet been proven. Factors that may contribute to the development of osteoarthritis include:
- obesity, which puts added strain on joints,
- jobs, or activities, that involve repetitive movements of a particular joint, or
- previous damage to the joint, such as from a sports injury.

Rheumatoid arthritis is caused by a fault in the immune system that makes the body to attack its own tissues. This may be inherited genetically (passed on from a family member).