A joint forms where the ends of two bones come together (e.g., hip, knee, elbow, shoulder, finger). Most of our joints facilitate movement. In normal anatomy, joint components stabilize the joint, allow bones to move freely, and protect the joint from the rigors of constant, everyday use.
The components include a capsule (a sac that encloses the joint) which is lined with synovium (i.e., a connective tissue membrane). The capsule is filled with synovial fluid, produced by the synovium, which helps to lubricate and nourish the cartilage and bones within the joint capsule. Cartilage covers the ends of the bones in a joint.
Joint pain can range from mild to severe. Acute joint pain may last a few weeks and go away without treatment. Chronic joint pain may last for months or years, if not a lifetime. If you experience joint pain, you likely will have limited range of motion, too. To restore normal joint function, it is important to know what is causing your joint pain, so that it can be properly treated. Some possible causes of joint pain include:
Joint injury (e.g., a fractured ankle) can compromise or weaken the structural components of the affected joint. Following joint injury, there may be bone bruising, bone remodeling, damage to surrounding structures (e.g., ligaments), or cartilage damage. If a joint is compromised, it may be painful when you attempt usual activities and sometimes at rest. Joint injury, even after it has healed, may increase the risk of developing painful osteoarthritis years later.
- Avascular necrosis
- Broken bone
Joint inflammation can occur with injury, disease, or infection. When a joint becomes inflamed, the synovium thickens. Synovial fluid production increases and the joint capsule swells. Circulating inflammatory cells move into the joint tissue. The process is known as active synovitis. With inflammation, there is usually redness, warmth, pain, and stiffness around or in the affected joint.
- Ankylosing spondylitis
- Juvenile rheumatoid arthritis
- Lyme disease
- Psoriatic arthritis
- Rheumatoid arthritis
Germs (bacterium, virus, or fungus) can travel through the body to a joint. The germ can enter the body through the skin, nose, throat, ears, or an open wound. An existing infection can spread to a joint. At the site of an infected joint, infectious arthritis can develop. With prompt treatment, infectious arthritis usually resolves. With delayed treatment or no treatment, joint damage may become permanent. It is important to recognize the warning signs.
Tumor In/Around Affected Joint
Tumors rarely impact joints but can if the joint is located near a bone or soft-tissue tumor. There are, however, two types of tumors (synovial chondromatosis and villonodular synovitis) which develop in the lining of the joints. Typically these tumors are benign, but they can be aggressive. Most often one joint is affected and it is painful until the tumor is removed via synovectomy (surgery to remove part or all of the synovium of a joint).
Other Conditions Related to Joint Pain or Arthralgia
- Paget's disease of bone
Joint Tumors. Merck Manual Home Health Handbook. Michael J. Joyce M.D. Last reviewed April 2008.
Joint Pain Causes. MayoClinic.com. Accessed 8/14/13.
Joint Injury in Young Adults and Risk of Subsequent Knee and Hip Osteoarthritis. Annals of Internal Medicine. Gelber AC, MD., et al. September 5, 2000.