What Causes Shoulder Pain When Sleeping?

1. Rotator Cuff Tendonitis and Tears

The rotator cuff is made up of four muscles and tendons that keep your shoulder stable. When these tendons become irritated (tendonitis) or develop small tears, the pain is often deep and aching.

During the day, gravity can help maintain space within the joint, but when you lie down, that space becomes smaller. This puts pressure on the already sensitive tendons, which can lead to sharp pain that may even wake you up.

2. Shoulder Bursitis

Bursae are tiny, fluid-filled sacs that help reduce friction between bones and soft tissues. When one of these sacs in the shoulder becomes inflamed, it swells and becomes painful.

Lying on the affected side presses directly on this area, making the pain worse. Many people describe bursitis as a warm, sore feeling that gets worse with pressure.

3. Adhesive Capsulitis (Frozen Shoulder)

Frozen shoulder is a condition characterized by progressive stiffness and inflammation of the shoulder capsule. Pain is usually strongest in the early stage, often called the freezing phase.

At night, since you are not moving much, the joint can become even stiffer. This is why the shoulder often feels very painful and hard to move in the morning.

4. Shoulder Impingement Syndrome

Impingement syndrome refers to pressure on the tendons or bursa from the upper edge of the shoulder blade. Impingement causes irritation that leads to pain, especially when raising the arm or sleeping with the arm under or above the head. Certain positions can further narrow the space in the shoulder joint, increasing pressure on the tendons and worsening discomfort.

Tips to Sleep More Comfortably

If your shoulder pain continues, it’s important to see a healthcare professional. However, these simple changes may help you sleep better:

• Sleeping on Your Back: This is considered an optimal position since it allows the shoulder joint to be in a comfortable position without any stress.
• Using Pillow Support Technique: In case one prefers lying on the side, it is recommended to use the side where there’s no pain by hugging a firm pillow. In this way, the arm will be supported and will not be strained.
• Do Some Stretching Exercises: Simple stretching before going to sleep, for example, pendulum movements, may help relax the shoulder joint.