Joints affected by osteoarthritis usually ache or become painful or stiff first thing in the morning, or during physical activity or shortly thereafter-This is one of the signs and symptoms of arthritis. They may also be stiff after periods of inactivity. There can be a loss of range of motion that makes certain movements difficult or impossible. For example, someone with arthritis can lose the ability to kneel or get up off the floor. As movement becomes restricted, balance tends to diminish from lack of use. The stiffness can often lead to joint swelling, which includes pain. Without intervention, the situation worsens and joints become increasingly more dysfunctional and incapable of allowing the body to move as it was intended.

While most laboratory tests will not show changes that result from osteoarthritis, researchers have found that there will be an elevation in an enzyme called C-reactive protein (CRP), which is a marker for inflammation. CRP levels in the blood have been shown to correlate well with CRP taken from the synovial fluid in the joint from patients with osteoarthritis, and there is growing evidence that elevated CRP levels are associated with severity of the clinical course (medical treatment) of osteoarthritis.

Cartilage

Cartilage is a flexible connective tissue consisting of three types, hyaline, elastic, and fibrocartilage, which are found throughout the body. In joints, hyaline cartilage lines the bones, providing a cushioning effect to the joints, helping to distribute forces during repetitive pounding movements like running or jumping, and acting like a shock absorber. If any aspect of the complex cartilage system breaks down, it can result in the degeneration of the entire joint. Because cartilage lacks a blood supply, it is a relatively vulnerable tissue. In arthritis, pressure on cartilage from movement and excessive weight bearing, along with chronic inflammation, can lead to thinning and damage.