Arthritis can be grouped into two main categories based upon the "localized" or "generalized" areas of the body or joints that are affected and then into sub-categories.

Localized Conditions: The arthritis that affects the soft tissue surrounding the joints or bones is considered soft tissue localized conditions, such as bursitis or tendonitis. Another sub-category of the localized conditions only affects one or only a few joints, such as a knee or hip.

Generalized Conditions: The first sub-category for generalized conditions are for those that affect the muscle and soft tissue where there is no evidence of swelling or inflammation. The condition is not associated with joint damage. Fibromyalgia is a common type of arthritis that is placed under this category.

The second sub-category of conditions includes arthritis conditions that involve inflammation that affects the entire body. Rheumatoid arthritis is an example of a condition under this category, as well as gout, and psoriatic arthritis. Other generalized arthritis conditions are polymyositis (muscles); systemic lupus erythematosus (skin, kidneys, or other organs); and vasculitis (any organ).

All arthritis conditions affect the musculoskeletal system and joints. Arthritis affecting the joint conditions causes pain, stiffness, inflammation, and damage to the joint cartilage. Cartilage is the tissue that covers the ends of the bones that protect them as they rub together. Cartilage is living tissue. Therefore, it has the same needs as other organs and glands. Cartilage cells are called chondrocytes. All chondrocytes will die and are usually replaced by new cartilage cells. However, over time inflammation can kill more cartilage cells than the body can replace. This is especially true if there has been an injury or there is not enough proper nutrients in the body to repair the joint. Damage from arthritis can also cause joint weakness, instability and deformities and interrupt daily activities. Typically, arthritis is treated with medication, physical therapy, and changes to the person's lifestyle. Joint replacement surgery is a last resort after healthcare providers have tried other less intrusive interventions to relieve the discomfort.

A person can have more than one type of arthritis. Arthritis includes more than 100 medical conditions that affect approximately 46 million adults and 300,000 children in the United States. Arthritis can start as early as infancy, while it is most common among adults over 60, primarily in the form of osteoarthritis. As the American population ages, the number of people with arthritis is increasing. Arthritis and related illnesses are the cause of major disability in the U.S. and costs over $124 billion a year in medical care and indirect expenses. Individuals can help prevent osteoarthritis by following a few simple steps:

-Maintain appropriate weight

-Consume fresh fruits and vegetables as a good source of vitamins c and d

-Make sure you are getting enough calcium (adults: 1000-1500mg per day)

-Exercise

-Avoid sports injuries