What is joint pain? Joint pain is the sensation of discomfort or soreness in a joint or joints of the body. Joints are the spaces or areas where two or more bones meet, such as the hip, knee, shoulder, elbow and ankle. Joint pain can occur with or without movement and can be severe enough to limit movement. People may describe joint pain as discomfort, inflammation, increased warmth or burning, soreness, stiffness, or pain. The joints allow our bones to move. They are made up of cartilage, ligaments, tendons, bursas (fluid-filled sacs that help cushion the joint), and the synovial membrane (lining of the joint capsule that secretes synovial fluid to lubricate the joint). Any of the structures in a joint can become irritated or inflamed in response to a variety of mild to serious diseases, disorders or conditions. Your joint pain may last briefly or it may be chronic, which is defined as lasting more than three months. Joint pain has many causes. Sudden joint pain can be due to a mild muscle or ligament sprain, bursitis, or a dislocation. Chronic joint pain can be a symptom of serious and even life-threatening conditions, such as rheumatoid arthritis, osteoarthritis, leukemia, or bone cancer. If you experience sudden joint pain with loss of mobility, contact a medical professional as soon as possible or seek emergency medical care. Early diagnosis and treatment can minimize discomfort and reduce your risk of serious complications. If the pain lasts for more than a few days or is accompanied by a fever, unexplained weight loss or other unusual symptoms, contact a medical professional as soon as possible.