Shoulder pain
Pain may be dull or aching and can become severe. It is often worse at night and may disturb sleep.
UNDERSTANDING THE CONDITION
What is frozen shoulder?
Frozen shoulder—also called adhesive capsulitis—is a condition in which the shoulder becomes painful and progressively stiff, making both everyday movement and assisted movement difficult.
MAIN SYMPTOMSPain and restricted movement
OTHER NAMEAdhesive capsulitis
ONSETUsually gradual
RECOVERYOften measured in months or years
A SIMPLE DEFINITION
The shoulder gradually loses movement because the capsule surrounding the joint becomes painful, thickened and tight.
Frozen shoulder affects the ball-and-socket joint where the upper-arm bone meets the shoulder blade.
The joint is enclosed by a flexible sleeve of connective tissue called the shoulder capsule. In frozen shoulder, changes within this capsule restrict the amount the joint can move. The restriction affects movement performed by the person and movement produced with help from someone else.
The condition commonly develops over time rather than after one obvious moment. Pain may be the most noticeable problem early on; stiffness may become more dominant later.
“Frozen shoulder” should not be used as a general label for every painful or stiff shoulder. Other conditions can produce similar symptoms, so appropriate assessment matters.
INSIDE THE SHOULDER
What changes in the joint?
The process is complex, but the central structure involved is the shoulder capsule.
A normally mobile shoulder
The head of the upper-arm bone moves within a shallow socket. A flexible capsule surrounds the joint and allows the arm to move through a wide range.
- Flexible joint capsule
- Room for smooth movement
- Movement coordinated with the shoulder blade
During frozen shoulder
The capsule becomes inflamed, thickened and tight. Bands of stiff tissue are commonly described as adhesions, and joint volume may reduce.
- Pain—often prominent early
- Progressive loss of movement
- External rotation is commonly restricted
COMMON FEATURES
What does frozen shoulder feel like?
Symptoms vary, but pain and a marked loss of shoulder movement are the defining features.
Increasing stiffness
Reaching overhead, behind the back or out to the side may become progressively more difficult.
Restricted assisted movement
The shoulder remains limited even when another person attempts to move it gently.
Everyday limitations
Dressing, washing, driving, working and comfortable sleeping can all be affected.
WHY DOES IT DEVELOP?
Sometimes there is no obvious cause.
Frozen shoulder can occur on its own or follow a period in which the shoulder has not been moving normally.
No clear trigger
The condition develops without a specific injury, operation or other obvious cause. This is often described as primary or idiopathic frozen shoulder.
Following another event
The condition develops after injury, surgery or another reason the shoulder has been painful or immobilised for a period.
ASSOCIATED FACTORS
Who is more likely to develop it?
Anyone can develop frozen shoulder, but several factors are associated with increased risk.
Age
It is most common in midlife, particularly between approximately 40 and 60.
Diabetes
Frozen shoulder is more common in people with diabetes and may behave differently.
Thyroid conditions
Both underactive and overactive thyroid disorders are associated with increased risk.
Injury or surgery
Risk may increase after an event that reduces normal shoulder movement.
Prolonged immobilisation
Keeping the arm still for an extended period can contribute to shoulder stiffness.
Other health conditions
Several neurological, cardiovascular and connective-tissue conditions have also been associated.
Having one or more risk factors does not prove that shoulder pain is frozen shoulder. Diagnosis depends on the complete clinical picture.
A CHANGING CONDITION
Frozen shoulder commonly moves through three overlapping stages.
The stages are useful for understanding the condition, but real experiences do not always follow a neat timetable.
Freezing
Pain usually becomes more prominent while movement gradually reduces.
Frozen
Stiffness remains marked. Pain may continue or begin to ease.
Thawing
Movement gradually improves, although recovery can be slow.
HOW IT IS IDENTIFIED
How is frozen shoulder diagnosed?
Diagnosis is usually based on the history of the problem and a physical examination.
Your history
A clinician asks how symptoms began, how they have changed and how they affect sleep and daily activities.
Movement assessment
Both self-directed and assisted shoulder movement are assessed, often including external rotation.
Ruling out alternatives
X-rays or other tests may be used when needed to exclude arthritis, fracture, rotator-cuff injury or another cause.
CONTINUE EXPLORING
Where should you go next?
Choose the resource that best matches your question.
WHEN TO SEEK HELP
Do not assume every painful shoulder is frozen shoulder.
Arrange a professional assessment if shoulder pain and stiffness persist or significantly limit movement.
Seek urgent medical help for severe symptoms following an injury, chest pain, sudden weakness, a visibly deformed shoulder, or a hot, red joint accompanied by fever or feeling unwell.
Sources and further reading
- American Academy of Orthopaedic Surgeons: Frozen Shoulder
- NHS: Frozen Shoulder
- Berkshire Healthcare NHS Foundation Trust: Frozen Shoulder Advice
This page provides general educational information and does not replace individual medical advice, diagnosis or treatment. Content should be reviewed by the site’s appointed clinical reviewer before publication.