09 Jan 2025
Shoulder pain is a very common condition with about 18-26% of the population reporting shoulder pain at any point in time. In patients who have more severe pain, the symptoms can affect simple activities such as changing clothes, carrying loads and sleep. This in turn results in lower work productivity and in some instances, dropping out of the workforce. In this article, we discuss some of the causes of shoulder pain that occur in the absence of an injury:
Shoulder pain is a very common condition, with approximately 18–26% of the population reporting shoulder pain at any point in time. In patients with more severe cases, shoulder pain symptoms often affect simple daily activities such as changing clothes, carrying loads, or sleeping. This, in turn, can reduce work productivity and, in some instances, dropping out of the workforce. In this article, we discuss some of the causes of shoulder pain that occur in the absence of an injury:
Shoulder Pain Arising from the Shoulder Joint
Frozen Shoulder
Frozen shoulder is also called “adhesive capsulitis”. Patients with this condition may experience a sudden onset of shoulder pain, even without a clear injury. Over time, the shoulder may also become stiff and lose its range of motion. While this can result from an injury (e.g. a fall, prolonged immobilisation of a fracture, or vaccination), many cases develop without any obvious cause.
The exact cause of frozen shoulder is not fully understood. However, it is thought that inflammation occurs within the joint, resulting in pain and subsequent fibrosis of the joint capsule. This fibrotic reaction results in a joint that is stiff and immobile.
Rotator Cuff Tendinopathy / Bursitis
The rotator cuff muscles are a group of muscles that control movement of the shoulder joint. The attachments of these muscles to the bone are called tendons. Repetitive use of these muscles over time can cause these tendons to become inflamed. Over time, if the inflammation is not addressed, it can result in the tendons fraying and eventually tearing.
Rotator cuff tendinopathy can cause pain and swelling throughout the shoulder. In many cases, the pain is worsened by overhead activities such as combing one’s hair or reaching the hands up.
Calcific Tendinitis
Calcium deposits in the rotator cuff tendons is another common cause of shoulder pain. It is not entirely clear what causes calcium deposits in the tendons, but there are postulations that they may be caused by microtrauma due to repetitive stress injury. Microtrauma can lead to small areas of bleeding and sequestration of calcium. These calcium particles can cause significant discomfort, often resulting in shoulder pain when pressing on the affected area. Fortunately, this condition often responds well to appropriate treatment, especially when assessed early at a pain clinic.
Arthritis
The shoulder joint is a cartilaginous joint – this means that the cartilages of the scapula and humeral bones glide over each other. These cartilages undergo constant wear and regeneration. However, as age progresses, the amount of wear exceeds cartilage regeneration, leading to thinning of the cartilages. Most patients with shoulder joint arthritis present with shoulder pain that is insidious in onset and progressive. However, in some patients, an acute inflammation of the joint can occur, resulting in sudden-onset pain.
Referred Pain
Referred pain refers to pain from other structures (other than the shoulder) which cause pain in the shoulder. This happens because the nerve supply of these areas overlaps with the nerves that supply the shoulder joint. In such cases, shoulder pain symptoms may be misleading, as the source of the pain is not actually within the shoulder itself. Examples of referred pain will include pain arising from:
- Cervical radiculopathy (Pinched nerve in the neck)
- Heart problems
- Pinched Suprascapular Nerve
- Shingles
When to See a Doctor?
If you have new, sudden-onset, severe, persistent, or worsening shoulder pain, you should always seek medical advice. In many cases, early and appropriate intervention from a pain management clinic can help prevent worsening of the condition.
If other symptoms are present (for example, if the shoulder pain is associated with chest pain or difficulty breathing), one should always seek urgent medical attention, as the pain may be arising from the heart (as in a heart attack).
