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.

Symptoms
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.

Causes
Illustration showing shoulder joint
Frozen shoulder
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.

Diagnosis
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.

Treatments
Most frozen shoulder treatment involves controlling shoulder pain and preserving as much range of motion in the shoulder as possible.
Medications
Over-the-counter pain relievers, such as aspirin and ibuprofen (Advil, Motrin, others), can help reduce pain and inflammation associated with frozen shoulder. In some cases, your doctor may prescribe stronger pain-relieving and anti-inflammatory drugs.
Therapy
A physical therapist can teach you stretching exercises to help maintain as much mobility in your shoulder as possible.
Surgical and other procedures
Most frozen shoulders get better on their own within 12 to 18 months. For persistent symptoms, your doctor may suggest:
Steroid injections
Injecting corticosteroids into your shoulder joint may help decrease pain and improve shoulder mobility.
Joint distension
Injecting sterile water into the joint capsule can help stretch the tissue and make it easier to move the joint.
Shoulder manipulation
In this procedure, you receive a general anesthetic so you'll be unconscious and feel no pain. Then the doctor moves your shoulder joint in different directions, to help loosen the tightened tissue. Depending on the amount of force used, this procedure can cause bone fractures.
Surgery
If nothing else has helped, you may be a candidate for surgery to remove scar tissue and adhesions from inside your shoulder joint. Doctors usually perform this surgery arthroscopically, with lighted, tubular instruments inserted through small incisions around your joint.