Shoulder pain that arises or intensifies when the body is at rest can be particularly noticeable when the shoulder is inactive, such as during sleep or prolonged sitting. This discomfort signals that underlying processes are at play even when the shoulder is not actively engaged.
Common Causes
One frequent cause of shoulder pain at rest involves the rotator cuff, a group of muscles and tendons stabilizing the shoulder joint. Conditions like tendinitis (tendon inflammation) or a tear in one of them can lead to discomfort that worsens when the arm is not in use. When relaxed, shoulder muscles may not adequately support the joint, allowing inflamed or damaged tissues to be compressed or stretched, leading to pain.
Another common culprit is bursitis, inflammation of a bursa (a small fluid-filled sac that reduces friction between bones and tendons). In the shoulder, the subacromial bursa can become inflamed, and when a person lies on the affected side or holds the arm in a certain position during rest, pressure on this inflamed bursa can cause pain. Osteoarthritis, a degenerative joint disease where cartilage cushioning the bones wears away, can also cause resting shoulder pain. The lack of movement during rest allows inflammatory mediators to accumulate in the joint, contributing to stiffness and pain.
Impingement syndrome occurs when rotator cuff tendons or the bursa become compressed in a narrow shoulder joint space. While often associated with movement, certain static positions, particularly lying down, can also compress these structures, leading to pain. Additionally, pain felt in the shoulder when resting can sometimes originate from problems in the neck. Conditions like cervical radiculopathy, where a nerve root in the neck is irritated or compressed, can refer pain down to the shoulder.
Why Rest Exacerbates Pain
Pain can become more pronounced during rest due to several physiological factors. When the body is active, the brain receives sensory inputs that can distract from or mask the sensation of pain. In a resting state, these distractions diminish, allowing the pain signals to become more noticeable.
Inflammation also plays a role; during activity, muscle contractions help circulate fluids, including inflammatory byproducts, away from injured tissues. When the shoulder is at rest, this natural pumping action reduces, allowing inflammatory substances to accumulate in the affected area. This buildup can increase pressure on nerve endings, intensifying the pain. Certain sleeping positions can also directly compress inflamed tendons or bursae.
Lying on the affected shoulder can put direct mechanical pressure on sensitive tissues, exacerbating discomfort. Even lying on the opposite side can cause the affected shoulder to rotate inward, stretching or compressing irritated structures.
Reduced blood flow to injured tissues during rest may also contribute to pain. The metabolic rate and blood circulation decrease during sleep, potentially hindering the natural healing process and allowing pain-producing chemicals to linger.
Initial Steps and Home Care
For managing shoulder pain at rest, several initial steps can provide relief. Applying ice to the affected area for 15-20 minutes, several times a day, can help reduce inflammation and numb the pain. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can also help manage pain and reduce inflammation.
Gentle stretching exercises, performed cautiously, can help maintain range of motion and prevent stiffness. For example, a pendulum stretch, where you lean forward and let your arm hang freely, can be beneficial. Paying attention to posture throughout the day, especially while sitting or working, can alleviate strain on the shoulder. Maintaining an upright posture helps align the shoulder and reduce stress on the joint.
Optimizing sleeping positions is important to minimize night pain. Avoiding sleeping directly on the painful shoulder is often recommended. Instead, try sleeping on your back with a small pillow under the affected arm for support, or on the unaffected side with a pillow to prop up the painful arm. This helps prevent compression and maintains a neutral position for the shoulder joint.
When to Seek Professional Help
Consult a healthcare professional for shoulder pain if it is severe and persistent, or suddenly worsens without a clear reason. An inability to move the arm through its full range of motion, or significant arm weakness, also warrants professional attention. These symptoms might indicate a more serious injury, such as a substantial tear.
If you experience numbness or tingling that extends down the arm or into the hand, this could suggest nerve involvement, potentially originating from the neck or shoulder. Pain that does not improve after several weeks of consistent home care, or pain that interferes with daily activities and sleep, should prompt a visit to a doctor. Persistent pain may require interventions beyond self-management strategies.
A doctor will begin with a thorough physical examination to assess range of motion, strength, and identify tender areas. They may also order imaging tests, such as X-rays or an MRI, to visualize bones and soft tissues. Common professional treatments for shoulder pain include physical therapy, which focuses on strengthening and flexibility exercises. Medications, including prescription NSAIDs or corticosteroid injections, may also be used to manage pain and inflammation.