Experiencing pain in the left collarbone can be concerning. This discomfort can stem from various sources, ranging from direct injury to more complex underlying conditions. Understanding the potential reasons behind left collarbone pain can help individuals better understand their symptoms.
Understanding the Collarbone and Surrounding Areas
The clavicle, or collarbone, is a slender, S-shaped bone located horizontally across the front of the shoulder. It extends from the sternum (breastbone) to the shoulder blade (scapula), connecting the axial skeleton and the upper limb. This bone provides structural support for the shoulder, enabling arm movements and transmitting forces from the upper limb to the body.
The collarbone articulates with the sternum at the sternoclavicular (SC) joint and with the acromion (part of the shoulder blade) at the acromioclavicular (AC) joint. Surrounding these joints are various muscles, ligaments, and nerves that contribute to shoulder movement and stability. Due to its exposed position, the clavicle and its adjacent structures are susceptible to injury and other conditions that can cause pain.
Common Musculoskeletal Causes
Pain in the left collarbone often arises from issues directly affecting the bones, muscles, or joints in the area. Fractures of the clavicle are common, often resulting from falls onto the shoulder or an outstretched arm, or from direct impacts. Symptoms typically include sharp pain, difficulty moving the arm, and sometimes a visible deformity or grinding sensation.
Sprains can affect the ligaments connecting the collarbone to other structures. An acromioclavicular (AC) joint separation involves damage to the ligaments that stabilize the joint between the collarbone and the shoulder blade, often caused by a direct blow to the shoulder. Sternoclavicular (SC) joint sprains, though less common, involve injury to the joint where the collarbone meets the breastbone. Both types of sprains can cause pain, swelling, and limited shoulder movement.
Muscle strains are another frequent musculoskeletal cause, occurring from overuse or sudden movements of muscles attached to the collarbone, such as the pectoralis or trapezius muscles. Arthritis, particularly osteoarthritis, can develop in the AC or SC joints due to wear and tear or previous injury. This condition causes pain, stiffness, and sometimes a clicking sensation, especially with arm movements.
Nerve-Related and Referred Pain Causes
Pain in the left collarbone can also originate from nerve compression or be referred from other parts of the body. Thoracic Outlet Syndrome (TOS) occurs when nerves or blood vessels are compressed in the narrow space between the collarbone and the first rib. This compression can lead to pain, numbness, tingling, or weakness in the shoulder, arm, and hand, and may be exacerbated by certain arm movements.
Referred pain from the heart is an important consideration, especially for left-sided collarbone discomfort. Conditions such as angina or a heart attack (myocardial infarction) can cause pain that radiates to the left arm, shoulder, or even the collarbone. This happens because the nerves from the heart and the left shoulder share common pathways, leading the brain to interpret the pain as originating in the shoulder. Pericarditis, inflammation of the sac surrounding the heart, can also present with chest pain that may radiate to the left shoulder or collarbone.
Pain can also be referred from lung conditions affecting the left side. For instance, pleurisy, an inflammation of the lining of the lungs, or pneumonia can cause chest pain that extends to the shoulder or collarbone area. Certain lung tumors, such as Pancoast tumors located at the top of the lung, can cause shoulder and arm pain that might include the collarbone region due to nerve irritation. Issues in the neck, specifically cervical radiculopathy (a pinched nerve in the cervical spine), can cause pain that travels down to the shoulder and collarbone.
When to Seek Medical Attention
While some collarbone pain may resolve with rest, certain symptoms warrant medical evaluation. Sudden, severe pain, particularly after a fall or injury, should be assessed by a healthcare professional. If the pain is accompanied by visible deformity, significant swelling, bruising, or an inability to move the arm, it is important to seek medical care.
For left-sided collarbone pain, specific symptoms signal a need for immediate attention. These include pain accompanied by chest tightness, shortness of breath, dizziness, sweating, or nausea, as these could indicate a cardiac issue. Any numbness, tingling, or weakness extending into the arm or hand may suggest nerve or blood vessel compression. Pain that worsens or does not improve with rest, or pain accompanied by fever, chills, or unexplained weight loss, should also prompt a visit to a doctor.