Causes of Arthritis
Most of the underlying causes of arthritis are unclear. Physicians know that physical trauma, such as an ankle sprain or a knee injury, can set the stage for osteoarthritis, the most common form of arthritis. Other causes are lack of physical activity, excessive weight or a joint defect such as bowlegs. . The aging process is a factor in osteoarthritis. That’s why it’s sometimes called the “wear-and-tear” arthritis. Genetic diseases can cause weak cartilage, leading to excess cartilage wear.
Genetic factors are important in the cause of some other types of arthritis, such as rheumatoid arthritis and several other less common forms. In contrast to osteoarthritis, which is a disease of the cartilage, forms of arthritis associated with an abnormal immune system, such as rheumatoid arthritis, are associated with inflammation of the lining of the joint. Other possible causes or factors include the environment (food, water and air), infectious agents (viruses, bacteria or fungi) or an imbalance of certain enzymes. Stress or other forms of emotional trauma can worsen symptoms.
Although the underlying causes of arthritis are unclear, the effects are not. Arthritis in its various forms may be associated with the following:
• Breakdown of cartilage: occurs in osteoarthritis, in rheumatoid arthritis and in other forms of inflammatory arthritis, such as lupus
• Inflammation of the lining of the joint (the synovial membrane), the blood vessels, muscles, tendons and ligaments: occurs in inflammatory arthritis and in other forms of arthritis that are more widespread in the body
• Development of crystals in the fluid of the joint (the synovial fluid): contributes to the development of attacks of acute gout and pseudogout
• Shortening or shrinkage of muscles or tendons, leading to joint deformities: can occur in any type of arthritis if the joint becomes immobilized
• A tightening of the skin: occurs mainly in scleroderma
• Damaged internal organs: can occur in rheumatoid arthritis and in other forms of inflammatory arthritis
• Loss of joint movement: occurs as a result of damage to a joint or weak muscles
• Decreased muscle strength: occurs if a joint is not moved for an extended period
• Decreased mobility: occurs as a result of long-term lack of exercise; may be permanent