Frozen Shoulder (Adhesive Capsulitis)

What happens in frozen shoulder

The shoulder is a ball-and-socket joint surrounded by a flexible capsule of connective tissue. In frozen shoulder, the capsule becomes inflamed, then thickens and contracts, and the fluid inside the joint decreases. Scar-like bands form. The result is a smaller, tighter joint space that restricts movement in every direction, especially turning the arm outward (external rotation).

Stages of frozen shoulder

Stages overlap and vary between people.

Symptoms

• dull or aching shoulder pain, often felt over the outer upper arm
• pain at night, especially lying on the affected side
• stiffness that limits reaching overhead, behind the back (fastening a bra, tucking in a shirt), or out to the side
• difficulty with dressing, hair brushing and reaching a seat belt
• loss of movement both when you try to move the arm yourself and when someone else moves it for you

That last feature, loss of passive movement, distinguishes frozen shoulder from rotator cuff problems, where someone else can usually move the arm further than you can.

Causes and risk factors

The exact cause is unknown. Frozen shoulder can be primary (no clear trigger) or secondary to another problem.

• Diabetes: the strongest risk factor. People with diabetes have frozen shoulder more often, in both shoulders more often, and with a slower recovery.
• Thyroid disease: both underactive and overactive thyroid.
• Immobilization: after injury, surgery (including breast surgery and heart surgery) or stroke.
• Age and sex: 40 to 60, more often women.
• Other conditions: Parkinson's disease, heart disease, Dupuytren's contracture and high cholesterol.

Frozen shoulder vs rotator cuff problems

Diagnosis

A doctor diagnoses frozen shoulder by examining active and passive shoulder movement. X-rays are taken to rule out arthritis or other bone problems, which can look similar. Ultrasound or MRI are used only when the diagnosis is uncertain or a rotator cuff tear is suspected. Blood sugar and thyroid tests may be checked.

Treatment

Pain relief

• NSAIDs such as ibuprofen or naproxen, and acetaminophen (paracetamol), especially in the painful stage. Follow the label dose; avoid NSAIDs if you have kidney problems, stomach ulcers or take blood thinners unless your doctor agrees.
• Heat or ice, whichever feels better.

Steroid injection

A corticosteroid injection into the shoulder joint is one of the most effective treatments for pain in the early stage, often allowing better sleep and exercise. Effects can last weeks to months. People with diabetes should monitor blood sugar, which can rise for a few days.

Physical therapy and exercises

Gentle stretching within tolerable pain levels maintains and gradually restores movement. Examples, done several times a day:

• Pendulum swings: lean forward and let the arm hang and swing in small circles.
• Finger walks: walk your fingers up a wall in front of you as far as comfortable.
• Towel stretch: hold a towel behind your back with both hands and use the good arm to pull the affected arm upward.
• Cross-body reach: use the good arm to lift the affected arm across your chest.

Aggressive stretching during the painful stage can make pain worse; a physical therapist can tailor exercises to your stage.

Procedures for persistent cases

• Hydrodilatation: injecting a large volume of fluid into the joint to stretch the capsule, usually with a steroid.
• Manipulation under anesthesia: the shoulder is moved firmly while you are asleep to break up tight tissue.
• Arthroscopic capsular release: keyhole surgery to cut the tight capsule.

These are considered when symptoms are severe and have not improved after several months of treatment.

Recovery and outlook

Most people improve substantially within 1 to 3 years, and many regain full or near-full movement. Some are left with minor stiffness that does not affect daily life. Recurrence in the same shoulder is uncommon, but the other shoulder is affected later in some people.

Frequently asked questions

What are the first signs of frozen shoulder?

Early signs are a gradually worsening ache in the shoulder or upper arm, pain at night, and difficulty with movements like reaching behind your back or overhead. Over weeks to months, stiffness increases and movement becomes limited in all directions.

How long does frozen shoulder last?

It typically lasts 1 to 3 years, moving through freezing, frozen and thawing stages. Treatment with injections and physical therapy can relieve pain and speed recovery. People with diabetes often take longer to recover.

What is the fastest way to cure frozen shoulder?

There is no instant cure. A steroid injection early on often relieves pain quickly, and a physical therapy program helps restore movement. For severe, long-lasting cases, hydrodilatation or surgery to release the capsule can speed recovery.

Why does frozen shoulder hurt more at night?

Lying on the affected shoulder compresses the inflamed capsule, and changes in position stretch it. Inflammation also tends to be felt more when you are still. Sleeping on your back or the other side with a pillow supporting the arm can help.

Is frozen shoulder linked to diabetes?

Yes. People with diabetes are several times more likely to develop frozen shoulder, more likely to have it in both shoulders, and tend to have more severe and longer-lasting symptoms. Good blood sugar control is part of managing it.