Rheumatologists are internal medicine physicians who sub-specialize in the diagnosis and treatment of disorders of the joints, muscles, soft tissues, and the connective tissues that surround bones and joints. While there are many conditions rheumatologists handle, among the more common are rheumatoid arthritis, osteoarthritis, and autoimmune diseases such as lupus and fibromyalgia.

Arthritis is a group of more than 100 different diseases. It is also a type of rheumatic disease. Rheumatic diseases may cause pain, stiffness, and swelling in the joints. They can also cause pain in other body structures. These include muscles, tendons, ligaments, and bones. Rheumatic diseases can also affect other areas of the body, such as internal organs. Some rheumatic diseases affect connective tissues. Others may be caused by an autoimmune disorder. This means the body’s immune system attacks its own healthy cells and tissues.

Arthritis and rheumatic diseases can affect anyone at any age or any race. But some diseases are more common in certain groups:

• Osteoarthritis is more common in older adults.
• The incidence of rheumatoid arthritis is 2 to 3 times higher in women than men.
• Fibromyalgia affects about 4 million adults in the U.S., more commonly in women.
• Gout is more common in men.
• Scleroderma is more common in women.
• Lupus affects women about 8 to 10 times more often than it affects men.
• Ankylosing spondylitis is more common in men.

Experts don’t know what causes most types of rheumatic disease. In many cases, the cause depends on the type of rheumatic disease. But researchers believe that some or all of these things may play a role:

• Genetics and family history
• Being overweight
• Injury
• Infection
• Nervous system problems
• Metabolic problems
• Too much wear and tear or stress on a joint or joints
• Environmental triggers
• Certain hormones