Pain in the top of the arm is a frequent complaint with various underlying causes. Understanding these common reasons can provide valuable insight, though it is not a substitute for medical evaluation.
Muscles and Tendons
Many instances of top of arm pain stem from issues with the muscles and tendons that move and stabilize the shoulder and arm. The biceps tendon, which connects the biceps muscle to the shoulder joint, is a common site for inflammation, a condition known as biceps tendinitis. This often results in pain or tenderness in the front of the shoulder that can extend down the upper arm, particularly worsening with overhead activities or lifting. Repeated overhead motions, common in sports like swimming or baseball, can lead to overuse and irritation of this tendon.
Another frequent cause involves the rotator cuff, a group of four muscles and their tendons that surround the shoulder joint, providing stability and enabling a wide range of motion. Rotator cuff tendinitis, or inflammation of these tendons, causes pain and swelling in the shoulder area, sometimes radiating down the side of the arm. This condition often arises from repetitive motions, overuse, or general wear and tear, and can make simple tasks like reaching overhead or sleeping on the affected side quite painful. In some cases, the pain may be accompanied by weakness or limited movement.
Joint and Bone Issues
Problems within the shoulder joint itself or its surrounding bony structures can also manifest as pain in the top of the arm. Shoulder impingement syndrome occurs when the tendons of the rotator cuff or the bursa (fluid-filled sacs that cushion joints) get pinched between the upper arm bone and the top outer edge of the shoulder blade, known as the acromion. This pinching sensation typically causes pain, especially when lifting the arm overhead or rotating it, and can lead to inflammation.
Bursitis, or inflammation of a bursa, is another common source of shoulder and upper arm pain. In the shoulder, subacromial bursitis, affecting the bursa located between the rotator cuff tendons and the acromion, is frequently observed. Symptoms include localized pain, tenderness, and sometimes swelling, with discomfort often increasing with movement or pressure on the affected area. Arthritis in the shoulder joint, characterized by inflammation and cartilage degeneration, can also contribute to a deep ache in the shoulder and upper arm.
Nerve Involvement
Pain felt in the top of the arm can sometimes originate from issues with nerves, even if the problem area is not directly in the arm itself. Cervical radiculopathy, often described as a “pinched nerve” in the neck, occurs when a nerve root in the cervical spine (neck) becomes compressed or irritated. This irritation can cause pain that radiates from the neck down the arm, sometimes described as burning or sharp. Along with pain, individuals might experience tingling, numbness, or weakness in the arm or hand, depending on which nerve is affected.
Another condition involving nerve compression is thoracic outlet syndrome (TOS), which occurs when nerves or blood vessels in the space between the collarbone and first rib become compressed. This can lead to pain, tingling, or numbness in the shoulder, arm, and hand, often worsening with overhead arm movements. The specific symptoms can vary depending on whether nerves, blood vessels, or both are compressed.
When to Consult a Doctor
While many instances of arm pain improve with rest and self-care, certain signs indicate the need for professional medical attention. It is advisable to consult a healthcare provider if the pain is severe, comes on suddenly, or follows a significant injury. Seek medical evaluation if the pain is accompanied by numbness, tingling, or weakness in the arm or hand. Persistent pain that does not improve with home remedies or worsens over time also warrants a medical assessment. Additionally, any arm pain coupled with symptoms like fever, redness, or swelling could indicate an infection requiring prompt medical attention.