Minor shoulder problems, such as sore muscles and aches and pains, are common. Shoulder problems develop from everyday wear and tear, overuse, or an injury. They can also be caused by the natural process of aging.
Your shoulder joints move every time you move your arms. To better understand shoulder problems and injuries, you may want to learn more about the shoulder joint itself. The shoulder is a ball-and-socket joint. It has three main bones: the upper arm bone (humerus), the collarbone (clavicle), and the shoulder blade (scapula). These bones are held together by muscles, tendons, and ligaments. The shoulder joint has the greatest range of motion of any joint in the body. Because of this mobility, the shoulder is more likely to be injured or cause problems. The acromioclavicular (AC) joint, which lies over the top of the shoulder, is also easily injured.
Shoulder problems can be minor or serious. Symptoms may include pain, swelling, numbness, tingling, weakness, changes in temperature or color, and changes in your range of motion. Shoulder injuries most often occur during sports activities, work-related tasks, projects around the home, or falls. Home treatment often can help relieve minor aches and pains.
Sudden (acute) injury
Injuries are the most common cause of shoulder pain.
A sudden (acute) injury may occur from a fall on an outstretched arm, a direct blow to the shoulder, or abnormal twisting or bending of the shoulder. Pain may be sudden and severe. Bruising and swelling may occur soon after the injury. Sometimes nerves or blood vessels may be injured or pinched during the injury. In that case, the shoulder, arm, or hand may feel numb, tingly, weak, or cold, or it may look pale or blue. Acute injuries include:
- Bruises (contusions). They occur when small blood vessels under the skin tear or rupture, often from a twist, bump, or fall. Blood leaks into tissues under the skin and causes a black-and-blue color that often turns purple, red, yellow, and green as the bruise heals.
- Injuries to the tough, ropy fibers (ligaments) that connect bone to bone and help stabilize the shoulder joints (sprains).
- Injuries to the tough, ropy fibers that connect muscle to bone (tendons).
- Pulled muscles (strains).
- Injuries to nerves, such as brachial plexus neuropathy.
- Separation of the shoulder. This occurs when the outer end of the collarbone (clavicle) separates from the end (acromion) of the shoulder blade because of torn ligaments. This injury occurs most often from a blow to a shoulder or a fall onto a shoulder or outstretched hand or arm.
- Damage to one or more of the four tendons that cover the shoulder joint (torn rotator cuff). This damage may occur from a direct blow to or overstretching of the tendon.
- Broken bones (fractures). A break may occur when a bone is twisted, struck directly, or used to brace against a fall.
- Pulling or pushing bones out of their normal position among the other bones that make up the shoulder joint (subluxation or dislocation).
You may not recall having a specific injury, especially if symptoms began slowly or during everyday activities. Overuse injuries occur when too much stress is placed on a joint or other tissue. This often happens when you overdo or repeat an activity. Overuse injuries include:
- Inflammation of the sac of fluid that cushions and lubricates the joint area between one bone and another bone, a tendon, or the skin. This inflammation is called bursitis.
- Inflammation of the tough, ropy fibers that connect muscles to bones (tendinitis). Bicipital tendinitis is an inflammation of one of the tendons that attach the muscle (biceps) on the front of the upper arm bone (humerus) to the shoulder joint. The inflammation usually occurs along the groove (bicipital groove) where the tendon passes over the humerus to attach just above the shoulder joint.
- Muscle strain.
- A frozen shoulder. This is a condition that limits shoulder movement. It may follow an injury.
- Overhead arm movements. They may cause tendons to rub or scrape against a part of the shoulder blade called the acromion. This rubbing or scraping may lead to abrasion or inflammation of the rotator cuff tendons. (This is also called impingement syndrome.)
Other causes of shoulder symptoms
Overuse and acute injuries are common causes of shoulder symptoms. Less common causes include:
- Muscle tension or poor posture.
- Pain that's coming from somewhere else in your body (referred shoulder pain).
- Breakdown of the cartilage that protects and cushions the shoulder joints (osteoarthritis).
- Calcium buildup in the tendons of the shoulder.
- An irritated or pinched nerve or a herniated disc in the neck.
- Infection in the skin (cellulitis), joint (infectious arthritis), bursa (septic bursitis), or bone (osteomyelitis).
- Cancer that has spread to the bones of the shoulder or spine.
- Abuse. Any shoulder injury (especially a dislocated shoulder) that can't be explained, doesn't match the explanation, or occurs more than once may be caused by abuse.
Treatment for a shoulder injury may include first aid, physical therapy, and medicine. In some cases, surgery is needed. Treatment depends on:
- The location and type of injury, and how bad it is.
- How long ago the injury occurred.
- Your age, health condition, and activities, such as work, sports, or hobbies.