What is osteoarthritis?

Osteoarthritis is a common form of arthritis, a disease that results in the breakdown of the cartilage that surrounds bones at the joints. Osteoarthritis is sometimes referred to as osteoarthrosis, degenerative joint disease, hypertrophic arthritis and degenerative arthritis. This serious and sometimes debilitating condition affects an estimated 27 million people in the United States, according to the Arthritis Foundation.

Osteoarthritis is characterized by the breakdown of cartilage in the joints. It can occur in any joint, but most often affects the hands, knees, spine or hips. The cartilage, which normally surrounds and protects the bones in the joint, becomes worn down, allowing the bones to rub against each other. This friction causes pain and swelling, and can lead to reduced motion in the afflicted joint. The rubbing of the bones can also cause the bones to develop growths, called spurs or osteophytes. After a while, pieces of bone or cartilage can rub off and float around in the fluid that surrounds the joint, which leads to increased pain and swelling. The joint pain worsens with movement and weight bearing, but lessens with rest.

It’s important to note that, unlike some forms of arthritis, osteoarthritis is confined to the joints and does not affect the function of any other organs.

There are two types of osteoarthritis. The first is primary osteoarthritis. This condition is characterized by the wear on the joints as described above, and is associated with aging. Most people will develop some form of primary osteoarthritis in later life. According to the U.S. National Library of Medicine and the National Institutes of Health, nearly everyone experiences at least some joint wear by age 70.

The other type of osteoarthritis is called secondary osteoarthritis. This condition is associated with a definite cause, such as heredity, obesity or injury. Obese people tend to suffer joint wear from carrying extra weight, particularly in the knees. Athletes who perform repetitive motions also tend to put more stress on their joints, which can eventually lead to secondary osteoarthritis. This type of repeated motion is also associated with certain types of jobs that put stress on various joints. Heredity plays a role as well; inherited bone abnormalities that affect the joints can lead to secondary osteoarthritis. For example, a person who is bowlegged has an increased risk of developing osteoarthritis.

People with osteoarthritis will usually experience some joint pain, which can be exacerbated by rainy weather or motion. The condition can progress gradually or quickly. As it progresses, joint mobility may become increasingly limited and interfere with daily life. As a consequence, some people with osteoarthritis are limited in their normal activities and job functions. This can lead to depression and feelings of helplessness. Fortunately, with treatment, most people with osteoarthritis are able to lead full and active lives.