There are many causes of joint pain and swelling, most of which fall into one of two categories: pain caused by inflammation and pain caused by injury. Inflammation encompasses arthritis, rheumatoid arthritis, bursitis, gout and other illnesses. Injury to joints is caused by unusual exertion or overuse of the joint.
Arthritis is the most common cause of joint pain. Osteoarthritis afflicts more people than any other type of arthritis, especially older adults. Sometimes called degenerative arthritis, osteoarthritis occurs when the cartilage in the joints break down, causing bones to rub against one other. Symptoms include joint pain, swelling, stiffness and loss of function.
Rheumatoid arthritis (RA) is an autoimmune disorder that causes pain and stiffness in joints. RA causes the immune system to malfunction, which produces inflammation in the lining of joints. This leads to joint deterioration, pain and decreased mobility. RA often occurs in small joints, such as those of the hands and feet, but it can affect any joint in the body.
Bursitis is another condition that causes joint pain and swelling. Bursa are small, fluid-filled sacs near joints that cushion bony knobs, allowing muscles and tendons to move easily over bone. These bursa might become tender and swollen because of excessive joint movement, pressure or trauma. Bursitis commonly occurs around shoulders, knees and hips.
Gout also causes joint pain and swelling. When the body has an excessive buildup of uric acid because of decreased kidney function, crystals are formed and deposited in the joints, leading to inflammation. Gout commonly affects the big toe. It can spread to other joints if left untreated.
There are other medical conditions that might have the side effect of joint pain and swelling. These include lupus, fibromyalgia and osteoporosis. Infectious diseases such as influenza, mumps, hepatitis and the chicken pox can also cause joint pain. When the immune system is forced to work overtime, white blood cells attack areas throughout the body, leading to joint aches and soreness.
Obesity is an indirect cause of joint pain and swelling. Carrying extra weight adds pressure to the joints and can accelerate the breakdown of cartilage. Research has shown that losing even a small amount of body weight can have a drastic effect on easing chronic joint pain.
Injuries are the other main cause of joint pain and swelling. Acute joint injuries might occur from a single, traumatic movement, and chronic joint injuries can occur from overuse. Both types of injuries might affect the ligaments, bursae or tendons surrounding the joint or the ligaments, cartilage and bones within the joint.
The most common types of joint injuries are sprains, strains and cartilage tears. A sprain is the over-extension of the ligaments that hold bones together in a joint. A strain is the over-extension of tendons, which are the connective tissues between a muscle and a bone. Sprains and strains occur when muscles and joints are forced to perform a movement, such as excessive stretching, for which they are not designed.
A cartilage tear is a tear in the rubbery tissue that connects bones at joints and prevents bones from grinding against one another. This type of injury is common in contact sports where pivoting and sudden stops occur. The knee joint is very susceptible to cartilage tears.
Treatment for joint pain resulting from injury entails resting the sore joint, protecting it from further injury, as well as the application of ice or heat and the use of over-the-counter pain medication. To treat joint inflammation, a doctor might recommend prescription medications. Acupuncture, magnet therapy and physical therapy are other common treatments for joint pain and swelling. Joint surgery is sometimes required for cases of advanced degeneration or severe injury.