Overview
Frozen shoulder, also called adhesive capsulitis, involves stiffness and pain in the shoulder joint. Symptoms typically begin slowly, then get worse. Over time, symptoms get better, typically within 1 to 3 years.
Having to keep a shoulder still for a long period increases the risk of developing frozen shoulder. This might happen after having surgery or breaking an arm.
Treatment for frozen shoulder typically involves range-of-motion exercises. Sometimes corticosteroids and numbing medicines injected into the joint are part of treatment.
Rarely, surgery is needed to loosen connective tissue in the shoulder joint so that it can move more freely.
Symptoms
Frozen shoulder typically develops slowly in three stages.
- Freezing stage. Any movement of the shoulder causes pain, and your ability to move the shoulder becomes limited. This stage typically lasts 2 to 9 months.
- Frozen stage. Pain may lessen during this stage. However, the shoulder becomes stiffer. Using it becomes harder. This stage lasts 4 to 12 months.
- Thawing stage. Your ability to move the shoulder begins to improve. This stage typically lasts 5 to 24 months.
For some people, the pain worsens at night, sometimes disrupting sleep.
Causes
The shoulder joint is enclosed in a capsule of connective tissue. Frozen shoulder occurs when this capsule thickens and tightens around the shoulder joint, restricting its movement.
It's unclear why this happens to some people. But it's more likely to happen after keeping a shoulder still for a long period, such as after surgery or an arm fracture.
Risk factors
Certain factors may increase the risk of developing frozen shoulder. Frozen shoulder is more common in people who have diabetes, heart disease or thyroid conditions. Parkinson's disease also may increase the risk.
Age and sex assigned at birth
People 40 and older, particularly women, are more likely to have frozen shoulder.
Immobility or reduced mobility
People who've had to keep a shoulder still are at higher risk of developing frozen shoulder. Restricted movement can be the result of many factors, including:
- Rotator cuff injury.
- Broken arm.
- Stroke.
- Recovery from surgery.
Systemic diseases
People who have certain diseases may be likely to develop frozen shoulder. Diseases that may increase risk include:
- Diabetes.
- Overactive thyroid, also called hyperthyroidism.
- Underactive thyroid, also called hypothyroidism.
- Cardiovascular disease.
- Parkinson's disease.
Prevention
One of the most common causes of frozen shoulder is not moving a shoulder while recovering from a shoulder injury, broken arm or stroke. If you've had an injury that makes it difficult to move your shoulder, talk with your healthcare professional about exercises that can help you maintain your ability to move your shoulder joint. These are called range-of-motion exercises.