Why Does Frozen Shoulder Cause Stiffness?

The shoulder capsule normally allows the ball-and-socket joint to move in several directions. With frozen shoulder, the capsule becomes inflamed and contracted. This reduces the space and flexibility needed for normal movement.

External rotation, where the forearm turns away from the body, is often one of the first and most restricted movements. Reaching overhead and behind your back may also become limited.

People may use their shoulder blade or lean their body to compensate. These changes can help complete a task, but they may also cause neck, upper-back or shoulder-blade discomfort.

What Are the Three Stages of Frozen Shoulder?

Frozen shoulder is often described using three overlapping stages: freezing, frozen and thawing. However, symptoms do not always follow a neat sequence. Pain and stiffness may overlap, and treatment decisions should reflect your current presentation rather than the stage name alone.

How Long Does Frozen Shoulder Last?

Recovery varies considerably. Some people improve within several months, while others have symptoms for one to three years. Pain may settle before full movement returns.

A long recovery does not mean that every person will have severe symptoms for the whole period. Progress often occurs gradually, with improvements in sleep, daily tasks and movement appearing at different times.

Diabetes, thyroid disease, the severity of movement loss and another shoulder condition may affect the course. A physiotherapist or doctor can review progress if recovery appears to have stalled.

What Causes Frozen Shoulder?

Many cases develop without a clear cause. This is sometimes called primary or idiopathic frozen shoulder.

Secondary frozen shoulder develops after another event or health problem. It may occur after:

• a shoulder or arm injury;
• shoulder, chest or breast surgery;
• a period when the arm has been kept still;
• a painful rotator cuff or bursa problem;
• a fracture or joint injury; or
• another medical condition associated with frozen shoulder.

After an injury or operation, follow the movement restrictions and rehabilitation advice given by your treating team. Moving too little can contribute to stiffness, but progressing too quickly may also aggravate healing tissues.

Who Is More Likely to Develop Frozen Shoulder?

Frozen shoulder most often affects adults over 40. It appears more commonly in women and in people with diabetes.

Other recognised associations include:

• thyroid conditions;
• prolonged shoulder immobilisation;
• recent trauma or surgery;
• Parkinson’s disease;
• cardiovascular disease; and
• a previous frozen shoulder in the other arm.

Having a risk factor does not confirm the diagnosis. Likewise, frozen shoulder can occur in people without any known risk factor. People with diabetes may also benefit from discussing their broader health management with their GP and reading about diabetes and musculoskeletal health.

How Is Frozen Shoulder Diagnosed?

Frozen shoulder is mainly diagnosed from your symptoms and physical examination. Your physiotherapist or doctor will ask how the problem began, how it affects sleep and daily tasks, and whether you have relevant health conditions or recent surgery.

The examination usually compares:

• active movement, where you move the arm yourself;
• passive movement, where the clinician gently moves the arm;
• shoulder rotation, elevation and behind-the-back reach;
• strength where testing is appropriate;
• neck and nerve-related symptoms; and
• movement of the shoulder blade and upper body.

Imaging is not always needed when the clinical pattern is clear. An X-ray may help rule out shoulder arthritis, fracture or another joint problem. Ultrasound or MRI may be considered when a significant tendon injury or another diagnosis is suspected.

What Else Can Feel Like Frozen Shoulder?

Several conditions can cause pain and reduced shoulder movement. Assessment may consider:

What Treatments May Help Frozen Shoulder?

Treatment depends on pain, stiffness, daily limitations, health history and the likely stage of the condition. No single approach suits everyone.

Education and activity changes

Understanding the condition can reduce uncertainty and help you pace daily activities. Temporary changes to reaching, lifting, driving and sleeping positions may reduce flare-ups.

Complete rest is rarely the long-term goal. Instead, aim to keep the arm moving within a tolerable range while avoiding repeated movements that cause a marked and lasting increase in pain.

Pain management

A GP or pharmacist can discuss suitable pain-relief medicines. Your medical history, other medicines and possible side effects need consideration before you start or change medication.

Heat, cold packs, supported sleeping positions and activity changes may provide short-term comfort for some people.

Physiotherapy

Shoulder physiotherapy may include education, movement advice, a graded home program and manual treatment where appropriate.

Physiotherapy aims to help you:

• manage pain and sleep disruption;
• maintain useful movement without repeated flare-ups;
• gradually improve shoulder mobility;
• maintain or rebuild shoulder and arm strength;
• reduce unhelpful movement compensation; and
• return to normal work, household and recreational tasks.

The treatment dose matters. Aggressive stretching during a highly painful stage can aggravate symptoms. Later, when pain has settled, stronger mobility and loading exercises may be appropriate.

Corticosteroid injection

A doctor may discuss a corticosteroid injection into the shoulder joint. It may provide short-term pain and function benefits, particularly during a painful early presentation. Benefits and risks vary, and injections do not replace an appropriate movement and rehabilitation plan.

Hydrodilatation

Hydrodilatation involves injecting fluid into the shoulder joint to expand the capsule. A local anaesthetic or corticosteroid may also be used. It may be considered in selected cases after medical assessment.

Specialist and surgical care

Most people begin with non-surgical care. Specialist review may be appropriate when pain and restriction remain severe despite suitable treatment.

Procedures such as manipulation under anaesthetic or arthroscopic capsular release are generally reserved for persistent cases. A specialist should explain the likely benefits, risks and rehabilitation requirements.

How Does Physiotherapy Change Across the Stages?

These categories overlap. Your physiotherapist should adjust the plan according to your response rather than follow a fixed timetable.

What Can You Do at Home?

1. Keep movement comfortable

   Move the shoulder regularly within a range that does not cause a marked or lasting flare-up.

2. Avoid forceful stretching

   Do not repeatedly force the arm through sharp pain, especially when night pain is prominent.

3. Support the arm during sleep

   A pillow under the elbow or forearm may reduce the pull on the shoulder. Some people prefer sleeping partly upright.

4. Adapt difficult tasks

   Bring commonly used items within easier reach and put the affected arm into clothing first.

5. Monitor the next-day response

   A mild short-term response may be acceptable. Reduce the dose if pain or sleep remains clearly worse afterwards.

When Should You Arrange an Assessment?

Arrange a physiotherapy or medical assessment when:

• shoulder pain and stiffness are getting worse over several weeks;
• sleep is regularly disturbed;
• you cannot reach overhead or behind your back as usual;
• both active and passive movement appear restricted;
• symptoms began after an injury, operation or period of immobilisation;
• you have diabetes or another associated medical condition; or
• progress has stopped or the diagnosis remains uncertain.

Frozen Shoulder FAQs

What to Do Next

If your shoulder is becoming progressively painful and stiff, an assessment can help determine whether frozen shoulder or another condition is causing the problem.

Your physiotherapist can assess your movement, explain the likely stage, identify suitable exercises and advise whether medical review or imaging may be useful.

Early care cannot guarantee a shorter recovery. However, a clear diagnosis and symptom-matched plan can help you avoid unsuitable exercises and manage daily activities more confidently.

References

1. Lee BC, Kim BS, Lee BJ, et al. Clinical practice guidelines for diagnosis and non-surgical treatment of primary frozen shoulder. Ann Rehabil Med. 2025;49(3):113–138. doi:10.5535/arm.250057.
2. Kirker K, O’Connell M, Bradley L, et al. Manual therapy and exercise for adhesive capsulitis: a systematic review with meta-analysis. J Man Manip Ther. 2023;31(5):311–327. doi:10.1080/10669817.2023.2180702.
3. Salamh P, Lewis J, Mattocks A, et al. Quality of clinical practice guidelines for frozen shoulder: a systematic review. Physiother Theory Pract. 2025;41(7):1495–1502. doi:10.1080/09593985.2024.2421881.
4. Healthdirect Australia. Frozen shoulder. Last reviewed July 2024.