Short answer
Pain lying on your shoulder at night is most often rotator cuff-related shoulder pain, where the tendons around the joint are irritated and dislike being compressed. Changing how you sleep usually helps quickly, and a progressive strengthening programme is the best-supported long-term fix. Gradual loss of movement in every direction with night pain can be frozen shoulder and needs assessment.
Common causes
Rotator cuff-related pain
Pain on the outside of the upper arm, worse lifting the arm or lying on it.
Bursitis
Often occurs together with rotator cuff pain and behaves the same way.
Frozen shoulder
Gradual stiffening in all directions, with strong night pain, more common between 40 and 60.
What usually helps right now
- Sleep on the other side hugging a pillow, so the sore arm rests on it.
- If you sleep on your back, put a small pillow under the sore arm.
- Keep using the arm within comfort during the day.
What to avoid
- Lying directly on the sore shoulder to “test” it.
- Complete rest; tendons need some load to recover.
When to book an assessment
- Night pain is lasting more than two weeks.
- You are losing range of movement.
- It is stopping you training.
Get urgent medical care if
- Shoulder or arm pain with chest pain, shortness of breath or sweating: call emergency services.
- Sudden weakness after a fall.
How we treat it
- AssessHistory, movement and clinical tests, with screening for anything that needs a doctor.
- ExplainA clear diagnosis in plain language, and what recovery usually looks like.
- TreatHands-on care where it helps: joint and soft tissue work, dry needling or adjustments.
- RebuildExercises and a training plan so it holds up, with an end point.
Questions
Why does my shoulder hurt more at night?
Lying on it compresses irritated tissues, and you are not distracted by the day.
Do I need an injection?
Exercise therapy is usually tried first. Injections are an option if progress stalls, discussed with your doctor.