Aging is linked with osteoarthritis (OA) of the joints. The hip and knee are affected most often.
Stiffness is also common as we get older. There are many reasons for this. Tendons and ligaments have less water in them. The drying effect makes the joints seem stiff. The cells that make up soft tissues are called collagen. Fewer new collagen cells are formed so we lose some elasticity in the joints and muscles.
There are other changes going on in the joints. The cartilage loses strength. Changes in the cells of the cartilage lead to OA. There is a thinning of the joint space as the cartilage breaks down. This loss in joint space can be seen on X-ray. It's the most common way to diagnose OA.
A medical doctor will use tests of motion and strength along with X-rays to make the diagnosis. An early diagnosis is best so that early treatment can limit problems.