Shoulder numbness during sleep often feels like tingling, “pins and needles,” or a temporary loss of feeling. While usually temporary, it can signal an underlying issue that warrants attention.
Common Reasons for Numbness
Sleeping position is a frequent cause of shoulder numbness. Resting directly on an arm or shoulder can compress nerves and blood vessels. This compression disrupts nerve signals, causing numbness or tingling.
Awkward positions, like sleeping with an arm extended above the head or tucked under the body, also contribute. These postures can stretch or compress nerve pathways, especially the brachial plexus, which supplies the shoulder, arm, and hand.
Beyond nerve compression, sustained pressure can impede blood flow. Restricted blood supply deprives nerves of oxygen and nutrients, contributing to numbness. This temporary restriction resolves once pressure is relieved and blood flow is restored.
Underlying Medical Conditions
More persistent medical conditions can also cause shoulder numbness during sleep. Cervical radiculopathy, a “pinched nerve” in the neck, is one such condition. This happens when a nerve root in the cervical spine is compressed or irritated, causing pain, weakness, or numbness that radiates down the shoulder and arm. Common culprits include disc herniations or bone spurs in the neck.
Thoracic outlet syndrome (TOS) is another potential cause. This condition involves compressed blood vessels or nerves in the thoracic outlet (between the collarbone and first rib). This compression affects nerves and blood vessels supplying the arm, leading to numbness, tingling, or weakness in the neck, shoulder, arm, and hand. TOS can result from anatomical variations, trauma, or repetitive activities.
Peripheral neuropathy, nerve damage outside the brain and spinal cord, can also cause numbness. While often affecting the hands and feet, it can extend to the shoulders and arms. Conditions like diabetes, vitamin B12 deficiencies, or autoimmune diseases can contribute. Circulatory issues, like atherosclerosis, can also contribute by reducing blood flow and depriving nerves of oxygen.
When to Consult a Doctor
While temporary shoulder numbness is often harmless, certain signs warrant medical advice. Seek investigation if numbness persists long after waking or doesn’t resolve quickly with position changes. Numbness with severe pain, muscle weakness, or atrophy also signals a potential underlying issue.
Bilateral numbness (in both shoulders or arms simultaneously) is another red flag. This suggests a systemic problem or broader nerve involvement. A medical evaluation is advisable if numbness worsens in intensity or frequency, or significantly disrupts sleep and daily activities.
Tips to Prevent Shoulder Numbness
Optimizing sleeping position can significantly reduce shoulder numbness. Sleeping on your back is recommended; it maintains neutral spinal alignment and distributes pressure evenly, preventing shoulder or arm compression. If side sleeping, use a body pillow to support the upper arm and prevent collapse.
Proper pillow support for the head and neck is important. A pillow that keeps the neck in neutral alignment prevents strain or compression of cervical spine nerves. Mattress quality also plays a role; a supportive mattress conforming to body curves reduces shoulder pressure points.
Light stretching before sleep can improve circulation and flexibility, potentially reducing nerve compression. Avoid prolonged arm elevation or repetitive shoulder movements before bed. Keeping arms below shoulder level during sleep can prevent nerve stretching or compression.