Different types of arthritis and rheumatic diseases have different signs and symptoms. In general, people who have arthritis feel pain and stiffness in the joints. Early diagnosis and treatment help decrease further joint damage and help control symptoms of arthritis and many other rheumatic diseases.

Some of these factors have been identified. For example, in osteoarthritis, inherited cartilage weakness or excessive stress on the joint from repeated injury may play a role. In rheumatoid arthritis, juvenile idiopathic arthritis, and lupus, patients may have a variation in a gene that codes for an enzyme called protein tyrosine phosphatase nonreceptor 22 (PTPN22).

Certain viruses may trigger disease in genetically susceptible people. For example, scientists have found a connection between Epstein-Barr virus and lupus. There are likely many genes and combinations of genes that predispose people to rheumatic diseases, and many different environmental factors that trigger them.

Gender is another factor in some rheumatic diseases. Lupus, rheumatoid arthritis, scleroderma, and fibromyalgia are more common among women. (See next section for details.) This indicates that hormones or other male-female differences may play a role in the development of these -conditions.

Rheumatic diseases affect people of all races and ages. Some rheumatic conditions are more common among certain populations. For example:

• Rheumatoid arthritis occurs two to three times more often in women than in men.
• Scleroderma is more common in women than in men.
• Nine out of 10 people who have lupus are women.
• Nine out of 10 people who have fibromyalgia are women.
• Gout is more common in men than in women. After menopause, the incidence of gout for women begins to rise.
• Systemic lupus erythematosus is more common in women than in men, and it occurs more often in African Americans and Hispanics than in Caucasians.