A disease that causes pain or stiffness in skeletal joints is known as what?

Arthritis is a term that specifically refers to a group of more than 100 different diseases and conditions that affect the joints, leading to pain, stiffness, swelling, and decreased range of motion. This condition can significantly impact a person’s mobility and quality of life. It encompasses various forms, including osteoarthritis and rheumatoid arthritis, each with distinct characteristics but sharing the common symptomatology associated with joint discomfort and rigidity.

The other options do not pertain to joint issues. Inflammation refers to the body's response to injury or infection, which can occur within joints but does not specifically denote a disease. Heart disease encompasses a range of cardiovascular conditions, while diabetes is a metabolic disorder primarily affecting blood sugar regulation. Neither of these conditions relates directly to pain or stiffness in skeletal joints as arthritis does, making arthritis the correct and most appropriate choice in this context.