Final answer:
Osteoarthritis is a joint disease that causes joint pain, stiffness, and other symptoms. It is commonly observed in the fingers and thumbs. Diagnosis is based on signs and symptoms, and may involve imaging techniques.
Step-by-step explanation:
Osteoarthritis (OA) is a joint disease characterized by the breakdown of joint cartilage and bone. The most common symptoms are joint pain and stiffness, typically observed in the fingers, thumbs, and other joints near the ends of the fingers. Other symptoms may include joint swelling and decreased range of motion. Osteoarthritis is usually diagnosed based on signs and symptoms such as joint deformities, pain, and stiffness, and may be confirmed through X-rays or other imaging techniques.