Shoulder pain is discomfort and pain that occurs around the shoulder joint—the joint that connects the upper arm to the chest and neck. Severe shoulder pain can be caused by several conditions, often because of the straining of the muscles, ligaments and bones of the shoulder joint. Athletes tend to incur injuries to their shoulders with higher frequency than inactive people, though some conditions unrelated to physical activity can also lead to shoulder pain.
One of the most common injuries to the shoulder joint that results in extreme pain is dislocation. The shoulder joint is a ball and socket type joint—a rounded piece of bone meets a cup-shaped piece, and both are held together by muscles and ligaments. This type of joint allows for great mobility, but it is also susceptible to injury. In a dislocation the ball part of the ball and socket joint pops out of socket, damaging the surrounding tissues and causing severe pain.
A separated shoulder is another common shoulder injury that results in extreme pain. In the shoulder the shoulder blade is connected to the collarbone with a number of ligaments. A blunt trauma to the top of the shoulder may cause these ligaments to be strained or break, which is known as a separated shoulder. Pain will generally diminish over time after the injury, and the injury normally recovers naturally by limiting the use of the shoulder joint. Any trauma that happens to break a bone in the shoulder area will also cause extreme pain.
Tendinitis is a condition in which the tendons of the body become irritated and inflamed, often because of recitative use or rubbing, which can result in sometimes severe pain. In the shoulder there is a small muscle called the rotator cuff, which assists the shoulder in rotating the arm inward and outward. The rotator cuff's tendons can sometimes rub on the bones and become afflicted with tendinitis. A severe injury to the shoulder might even result in a tear to the rotator cuff muscle.
Strains, sometimes called muscle pulls, happen when a muscle is overstressed or overstretched and is partially or fully torn. If the muscles of the shoulders are used for heavy lifting, they may become strained, which will result in pain. Even if the muscles are not strained, overtaxing them will likely result in severe aches as the muscles struggle to rebuild themselves from the tiny tears caused by intense use.
Rheumatoid arthritis is a condition characterized by the painful inflammation of a joint. Joint pain from arthritis can be extreme, especially when experienced in a large joint such as the shoulder. Rheumatoid arthritis can lead to joint damage, which can further exacerbate pain and lead to other problems.