Arthritis is a broad term that covers a group of over 100 diseases. It has everything to do with your joints -- the places where your bones connect -- such as your wrists, knees, hips, or fingers. But some types of arthritis can also affect other connective tissues and organs, including your skin.
About 1 out of 5 adults have some form of the condition. It can happen to anyone, but it becomes more common as you age.
In osteoarthritis,the cushions on the ends of your bones, called cartilage, wear away. That makes the bones rub against each other. You might feel pain in your fingers, knees, or hips.
It usually happens as you age. But if underlying causes are to blame, it can begin much sooner. For example, an athletic injury like a torn anterior cruciate ligament (ACL) or a fracture near a joint can lead to arthritis.