If shoulder pain is left untreated, the pain can become chronic and limit your daily and recreational activities.
1) Tendonitis and Impingement
Tendinitis is the inflammation of the shoulder tendons (connective tissue that attaches muscle to bone). Impingement of the rotator cuff tendons (tendons that surround the shoulder joint, keeping the head of the upper arm bone firmly within the shallow socket of the shoulder) occurs under the acromion process (projection of the shoulder blade that forms the tip of the shoulder). Impingement happens when the arm is raised overhead repeatedly, raised overhead with a heavy load, or when one sleeps on their shoulder.
2) Rotator cuff tears
Rotator cuff tears occur when one experiences a trauma such as a fall or as a result of the rotator cuff tendons gradually wearing out.
Symptoms of rotator cuff tears include pain in the shoulder that often radiates down to the middle of the arm, especially when the arm is raised overhead, weakness. In severe cases, a complete loss of the ability to lift the arm.
3) Frozen shoulder
Frozen shoulder is a condition in which the shoulder joint has become stuck and its movement is limited. It is most often caused by the inflammation (swelling, pain, and irritation) and scarring of the joint capsule (tissue that envelopes the shoulder joint), restricting shoulder movement and making movement painful.
Immobilisation of the shoulder (following an arm injury, for example) and inflammation of the muscles and/or tendons can lead to a frozen shoulder.