Arthritis (arthro-, joint + -itis, inflammation; plural: arthritides) is a group of conditions where there is damage caused to the joints of the body. Arthritis is the leading cause of disability in people over the age of 55.

There are many different forms of arthritis, each of which has a different cause. The most common form of arthritis, osteoarthritis (also known as degenerative joint disease) occurs following trauma to the joint, following an infection of the joint or simply as a result of aging. Furthermore, there is emerging evidence that abnormal anatomy may contribute to early development of osteoarthritis.

Around 107,000 people are said to be hospitalized thanks to bad reactions with NSAIDs - the group of drugs Vioxx belonged to.

There are different forms of arthritis, but the two most commonly known are rheumatoid and osteoarthritis.

Rheumatoid arthritis is an autoimmune disease. This is when the body fails to recognize its own constituent parts as "self" and begins to attack its own cells and tissues - in this case, the joints. Being a systemic disease, it often affects other body tissue, including skin, blood vessels, heart, lungs and muscles.

Osteoarthritis on the other hand, is a degenerative condition caused by a wearing of the cartilege that cushions the joints. This causes pain and loss of mobility which in turn may lead to muscular atrophy after a while, bringing further complications.

How Common Is Arthritis?

Arthritis is very common. It has been estimated that as many as 70 million Americans -- or about one in three -- have some form of arthritis or joint pain. It is a major cause of lost work time and serious disability for many people. Osteoarthritis, the most common form, affects more than 20 million Americans. Arthritis affects people of all ages, but is more common in older adults.

Causes

The exact cause of arthritis is unknown. However, there are a number of risk factors associated with various arthritic conditions.A risk factor increases the chances that a person will develop a disease or condition. Some researchers suspect that rheumatoid arthritis is triggered by an infection - possibly a virus or bacterium - in people with an inherited susceptibility. Although the disease itself is not inherited, certain genes that create an increased susceptibility are. People who have inherited these genes won't necessarily develop rheumatoid arthritis.

Symptoms

If you have arthritis, you may experience:

* Joint pain
* Joint swelling
* Stiffness, especially in the morning
* Warmth around a joint
* Redness of the skin around a joint
* Reduced ability to move the joint

Risk Factors

Certain factors have been shown to be associated with a greater risk of arthritis. Some of these risk factors are modifiable while others are not.

Treatment

Treatments for arthritis have improved in recent years. Most treatments involve medications. But in some cases, surgical procedures may be necessary. Drug classes used to treat arthritis include:

* NSAIDs (nonsteroidal anti-inflammatory drugs)
* COX-2 Inhibitors
* Pain Medication (analgesics)
* Corticosteroids
* DMARDs (disease-modifying anti-rheumatic drugs)