What condition does Arthritis primarily affect?

Arthritis primarily affects the joints in the body. It is characterized by inflammation and pain in the joints, which can lead to reduced mobility and decreased quality of life for those affected. The condition involves the wear and tear of cartilage, which is the protective tissue at the ends of bones within joints. While arthritis can impact surrounding structures, its most significant and direct effect is on the joints themselves, often causing symptoms such as swelling, stiffness, and difficulty in movement.

The other choices—muscle tissue, ligaments, and cartilage only—do not encapsulate the primary impact of arthritis. Although cartilage degradation is a component of certain types of arthritis, such as osteoarthritis, the condition primarily manifests through joint inflammation and dysfunction rather than limiting its effects solely to cartilage or involving muscles and ligaments specifically. Understanding this helps clarify why the focus is on joints in relation to arthritis, as they are the structures most directly affected by the inflammatory processes.