Arthritis is the loss or damage of joint (articular) cartilage. Cartilage is a smooth, shiny surface that covers the ends of your bones. Normally, when cartilage rubs together, you have smooth and painless motion. When your cartilage degenerates, however, you can suffer from pain and limitation of motion.When you have arthritis, your soft tissues — the [no-glossary]muscles[/no-glossary], [no-glossary]tendons[/no-glossary], and [no-glossary]ligaments[/no-glossary] surrounding and supporting the joint — can also become weak and unable to function.

About one in every 3 Americans suffers from some form of arthritis — the number one cause of disability in the U.S., according to the Centers for Disease Control and Prevention.