Frozen shoulder is a condition that occurs when inflammation in the shoulder capsule leads to a "sticking" of the head of the humerus, or upper arm bone, inside its socket. This condition, more formally known as adhesive capsulitis, is most common among people around 40 to 65 years old and occurs more often in women than in men. Interestingly, though the hip is also a "ball and socket joint" like the shoulder, adhesive capsulitis doesn’t affect the hip or any other major joint in the body such as the knee or elbow—it only occurs in the shoulder.

Adhesive capsulitis is still considered "idiopathic" by the medical community, meaning that its origin or exact cause is unknown. What is known is that inflammation is a critical factor in setting off what appears to be a cascade of chemicals in the body that specifically irritate the shoulder joint. Sometimes a frozen shoulder can arise due to an injury, but many patients say it seems to "come out of nowhere."

Patients often wake up one day with intense pain in one shoulder that tends to feel progressively stiffer over time, resulting in a significantly reduced range of motion in the upper arm.

Frozen shoulder tends to go through three phases or stages. In the early stage, there is pain in the shoulder that gradually worsens, but the arm’s range of motion usually is unaffected. In other words, the shoulder hurts, but it remains functional.

During stage two, the range of motion diminishes, and inflammation in the shoulder joint worsens. Stage three is often called the "thawing" phase, where the pain and range of motion gradually improve. Every case is different. Some frozen shoulders take months to resolve, while others can take years.

The first frozen shoulder experience tends to occur in the non-dominant arm. Unfortunately, the risk of experiencing it in the other shoulder increases after the first episode.

A doctor’s diagnosis of adhesive capsulitis involves a complete history and physical examination that includes testing the active and passive motion of the affected shoulder. Sometimes the doctor will also take an X-ray of the shoulder to rule out other conditions such as arthritis.

Once a diagnosis is made, treatment can consist of a variety of approaches primarily aimed at reducing pain, decreasing inflammation and restoring range of motion. Treatments may include anti-inflammatory medications, either taken orally or by injection, and physical therapy. At-home exercises may also be recommended so that the patient continues to work on improving the shoulder’s range of motion while it heals.

Especially in cases where recovery takes a year or longer, treatments like these are essential to help reduce the risk of permanent range-of-motion loss. In severe cases and when conservative treatments fail to provide relief, a surgical procedure called arthroscopic capsular release may be recommended. During this procedure, the surgeon will release the joint capsule that has stiffened while also removing any built-up scar tissue.
 

Some factors beyond age and gender can increase a person’s risk of developing frozen shoulder. Genetics appears to be a factor, with a higher risk for people with a first-degree relative who experienced the condition. Studies suggest that people with Type 2 diabetes may be up to five times more prone to developing adhesive capsulitis than other people are. In addition, people who have thyroid disorders and those who recently underwent breast cancer or heart surgery appear to face a heightened risk.

Even though the exact cause of adhesive capsulitis remains a mystery, effective treatments are available. Be sure to talk to your doctor, preferably an orthopedic specialist, who can help you embark on the best healing treatment path. No person should have to live with the pain or disability from a frozen shoulder.

Read: Athletes Who Throw Deal With Shoulder Injury Risks