What is a hallmark of arthritis?

The hallmark of arthritis is joint inflammation. This condition primarily affects the joints, leading to swelling, pain, stiffness, and reduced range of motion. Inflammation is a key reaction of the body's immune system, which can occur as a response to joint damage or degeneration, characteristic of various types of arthritis, including osteoarthritis and rheumatoid arthritis.

While bone fractures, skin rashes, and muscle spasms can be associated with different health conditions, they are not defining traits of arthritis itself. Bone fractures may occur due to various reasons, including osteoporosis or injury, but they do not characterize arthritis. Skin rashes can result from autoimmune disorders but are not typical features of arthritis. Muscle spasms can be observed in numerous medical conditions, including some types of arthritis, but they do not specifically define the disease. Thus, joint inflammation is the primary and most indicative sign of arthritis.