Final answer:
Joint pain and stiffness are major warning signals for arthritis, specifically osteoarthritis, which results from the breakdown of joint cartilage and bone.
Step-by-step explanation:
One of the basic seven major warning signals for arthritis is joint pain and stiffness. Osteoarthritis (OA) is a joint disease that often results in these symptoms, along with swelling, decreased range of motion, and eventually constant pain that impacts daily activities. As the articular cartilage within synovial joints breaks down due to factors such as aging, physical stress, or being overweight, the joints respond with an increase in synovial fluid, leading to swelling and discomfort. Diagnosis is typically based on signs like joint deformities and symptoms including pain and stiffness, with treatments focusing on pain relief and maintaining joint function.