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

First, your doctor will take a detailed medical history to see if arthritis or another musculoskeletal problem is the likely cause of your symptoms.

Next, a thorough physical examination may show that fluid is collecting around the joint. (This is called an "effusion.") The joint may be tender when it is gently pressed, and may be warm and red (especially in infectious arthritis and autoimmune arthritis). It may be painful or difficult to rotate the joints in some directions. This is known as "limited range-of-motion."

In some autoimmune forms of arthritis, the joints may become deformed if the disease is not treated. Such joint deformities are the hallmarks of severe, untreated rheumatoid arthritis.

Tests vary depending on the suspected cause. They often include blood tests and joint x-rays. To check for infection and other causes of arthritis (like gout caused by crystals), joint fluid is removed from the joint with a needle and examined under a microscope. See the specific types of arthritis for further information.