Frozen shoulder, also known as adhesive capsulitis, is a condition characterized by stiffness and pain in your shoulder joint. Signs and symptoms typically begin gradually, worsen over time and then resolve, usually within one or two years.
Your risk of developing frozen shoulder increases if you’re recovering from a medical condition or procedure that affects the mobility of your arm such as a stroke or a mastectomy.
Treatment for frozen shoulder involves stretching exercises and, sometimes, the injection of corticosteroids and numbing medications into the joint capsule. In a small percentage of cases, surgery may be needed to loosen the joint capsule so that it can move more freely.
Frozen shoulder typically develops slowly, and in three stages. Each of these stages can last a number of months.
- Painful stage. During this stage, pain occurs with any movement of your shoulder, and your shoulder’s range of motion starts to become limited.
- Frozen stage. Pain may begin to diminish during this stage. However, your shoulder becomes stiffer, and your range of motion decreases notably.
- Thawing stage. During the thawing stage, the range of motion in your shoulder begins to improve.
For some people, the pain worsens at night, sometimes disrupting normal sleep patterns.
The bones, ligaments and tendons that make up your shoulder joint are encased in a capsule of connective tissue. Frozen shoulder occurs when this capsule thickens and tightens around the shoulder joint, restricting its movement.
Doctors aren’t sure why this happens to some people and not to others, although it’s more likely to occur in people who have recently experienced prolonged immobilization of their shoulder, such as after surgery or an arm fracture.
Although the exact cause is unknown, certain factors may increase your risk of developing frozen shoulder.
Age and sex
People 40 and older are more likely to experience frozen shoulder. Most of the people who develop the condition are women.
Immobility or reduced mobility
People who have experienced prolonged immobility or reduced mobility of their shoulder are at higher risk of developing frozen shoulder. Immobility may be the result of many factors, including:
- Rotator cuff injury
- Broken arm
- Recovery from surgery
People who have certain medical problems appear to be predisposed to develop frozen shoulder. Examples include:
- Overactive thyroid (hyperthyroidism)
- Underactive thyroid (hypothyroidism)
- Cardiovascular disease
- Parkinson’s disease
During the physical exam, your doctor may ask you to perform certain actions, to check for pain and evaluate your range of motion. These may include:
- Hands up. Raise both your hands straight up in the air, like a football referee calling a touchdown.
- Opposite shoulder. Reach across your chest to touch your opposite shoulder.
- Back scratch. Starting with the back of your hand against the small of your back, reach upward to touch your opposite shoulder blade.
Your doctor may also ask you to relax your muscles while he or she moves your arm for you. This test can help distinguish between frozen shoulder and a rotator cuff injury.
Frozen shoulder can usually be diagnosed from signs and symptoms alone. But your doctor may suggest imaging tests such as X-rays or an MRI to rule out other structural problems.