In osteoarthritis, what is the primary source of pain?

In osteoarthritis, the primary source of pain arises from the degeneration of cartilage within the joints. As the cartilage wears away over time, bone surfaces can come into direct contact with each other, leading to increased friction. This friction generates pain signals due to damage to the underlying bone and irritation of the synovial tissue surrounding the joint. Additionally, the process of osteoarthritis involves inflammation, which can exacerbate pain and contribute to the overall discomfort experienced by individuals.

While muscle spasms, fluid accumulation, and joint instability can contribute to pain in various contexts, the root cause of pain in osteoarthritis specifically relates to the degradation of cartilage and subsequent friction between the bones involved in the affected joint. This makes friction from cartilage degeneration the key element in the pain experienced by those with osteoarthritis.