bone, joint, and muscle disorders
Joint Pain: Single Joint
Evaluation of Pain in a Single Joint
The following information can help people decide when a doctor’s evaluation is needed and help them know what to expect during the evaluation. In people with pain in a single joint, certain symptoms and characteristics are cause for concern and are more likely to require immediate treatment. They include Sudden or severe pain Joint redness, warmth, swelling, or limitation of motion Fever Broken, red, warm, or tender skin near the joint Presence of a bleeding disorder, use of anticoagulants ("blood thinners," for example,warfarin), or abnormal blood hemoglobin (for example, sickle cell disease) Signs of sudden illness other than joint pain Possibility of a sexually transmitted infection (for instance, due to unprotected sex with a new partner) People with warning signs should see a doctor right away. Doctors are better able to treat symptoms more rapidly and completely if treatment occurs early in certain disorders, including crystal-induced arthritis, hemarthrosis, and infectious arthritis. People without warning signs, particularly if the cause of pain is known (for example, if typical pain recurs in a joint affected by osteoarthritis or if pain occurs after a minor injury) and symptoms are mild, can wait a few days and see whether symptoms resolve before seeing a doctor. Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of the pain and the tests that may need to be done (see table). Doctors ask about the following: When the pain started, how it has progressed, where it is located, and its severity What makes the pain better or worse (for example, movement, weight-bearing exercise, or rest) Previous injuries or previous joint pain Symptoms in other joints (such as swelling) Risk factors for sexually transmitted infections and Lyme disease Known disorders, particularly those that could cause or contribute to joint pain (such as osteoarthritis, gout, or sickle cell disease) The physical examination focuses on the joints for signs of inflammation (including swelling, warmth, and rarely redness), tenderness, limitation of motion, and noises made when the joint moves (called Joint Noises ). Doctors compare the affected joint with the unaffected joint on the opposite side of the body to look for any subtle changes. Doctors may also look for signs of infection elsewhere on the body, particularly on the skin and genitals. Several findings from the history and examination give clues to the cause of joint pain: Based on the examination, doctors can usually tell whether the source of the pain is the joint or nearby structures. For example, if only one side of a joint seems abnormal, the source of the pain is probably outside of the joint. Based on the examination, doctors can usually tell whether fluid is in the joint. Inflammation that develops over hours is usually caused by crystal-induced arthritis, particularly if similar symptoms have occurred previously. Infectious arthritis is another major cause of acute arthritis. Fever is most often caused by infectious arthritis or crystal-induced arthritis. The need for tests depends on what doctors find during the history and physical examination, particularly whether warning signs are present. Possible tests include Testing of joint fluid X-rays and other imaging tests Sometimes blood tests Doctors usually test the fluid in the joint if the joint is swollen. Doctors extract the fluid from the joint by first sterilizing the area with an antiseptic solution and then numbing the skin with an anesthetic. Then a needle is inserted into the joint and joint fluid is withdrawn (a procedure called Joint aspiration (arthrocentesis) or arthrocentesis). This procedure causes little or no pain. The fluid is usually tested for, among other things, bacteria that can cause infection and is examined under a microscope for crystals that cause gout and related disorders. Sometimes doctors do not test the fluid if the cause of the joint pain is obvious, for example, the pain occurs after an injury or fluid accumulates repeatedly in a joint with a chronic joint disorder such as osteoarthritis. X-rays may be taken, but they are usually unnecessary in people with acute arthritis. X-rays do not show abnormalities of soft tissues or cartilage. X-rays are most helpful in diagnosing fractures and sometimes bone tumors or osteonecrosis. Computed tomography (CT) and magnetic resonance imaging (MRI) (MRI) or Laboratory Tests are occasionally necessary, for example, to help diagnose or rule out Lyme disease. 