Published by ProMOTION Physiotherapy Clinical Team · Clinically reviewed · Published: 25 September 2026
Frozen shoulder, also called adhesive capsulitis, is a condition where the capsule surrounding the shoulder joint thickens and tightens, gradually restricting movement and causing pain that is often worse at night. It usually develops without a clear injury, most commonly between ages 40 and 60, and is more common with diabetes or a history of another shoulder problem. Left alone it typically resolves, but the course can run from several months to two or three years, longer than most people expect.
The most common driver is an inflammatory and then fibrotic response inside the joint capsule itself, not a problem with the muscles, tendons or bones around it, which is why frozen shoulder can feel confusing compared with a typical strain: nothing was torn, yet the shoulder stiffens regardless.
What to do next depends on which stage you are in. Early on, when pain dominates and movement is only mildly restricted, gentle activity within your pain limits and an assessment to confirm the diagnosis are the priority. Once stiffness has become the main problem, targeted physiotherapy and, for some people, an injection can meaningfully shorten how disabling the condition feels day to day, even if it does not dramatically shorten the total timeline.
The rest of this article explains what is happening inside the joint, gives you a way to work out which stage you are in, sets out what the evidence actually says about treatment, flags when shoulder pain needs urgent rather than routine care, and covers what assessment and rehabilitation look like at our Davidsons Mains clinic.
Why frozen shoulder happens
Frozen shoulder happens when the capsule that wraps the shoulder joint becomes inflamed, thickens, and then contracts, physically shrinking the space the joint has to move through rather than any single structure being torn or damaged.
The capsule is a loose sleeve of connective tissue that normally allows the shoulder its exceptional range of motion. In frozen shoulder, fibroblasts within the capsule proliferate and lay down excess collagen, similar in some ways to a scarring process, which stiffens the tissue and reduces its ability to stretch. This is why frozen shoulder movement loss is described as “capsular pattern”: external rotation is lost first and most severely, followed by abduction and internal rotation, a pattern that differs from a rotator cuff tear or impingement, where movement loss is usually more selective and linked to a specific direction of load. The exact trigger for this fibrotic response is not fully understood, but it is strongly associated with diabetes, thyroid disorders, and periods of shoulder immobility, for example after a fracture, surgery, or a stroke affecting that arm. Pain is often worst at night because lying down changes the pressure and position of the already-tight capsule, and there is little to distract from it compared with daytime activity. Rest alone does not resolve frozen shoulder because the problem is structural tightening of the capsule itself; the tissue needs to be moved and gradually loaded within tolerance to maintain and slowly regain range, not protected into further stiffness.
Work out your stage in three steps
Frozen shoulder moves through three overlapping stages, and knowing roughly which one you are in changes what “actually helps” looks like.
| What you notice | Likely stage | What it suggests |
|---|---|---|
| Gradual ache, worse at night, movement only mildly reduced so far, pain is the main complaint | Freezing (stage 1, often 2 to 9 months) | Assessment to confirm diagnosis, pain management, gentle range-of-motion work within comfort |
| Pain has eased somewhat but the shoulder feels genuinely stuck, reaching overhead or behind your back is significantly limited | Frozen (stage 2, often 4 to 12 months) | Structured physiotherapy stretching and mobilisation; injection may be considered alongside |
| Movement is gradually returning without a specific treatment change, stiffness slowly loosening | Thawing (stage 3, often 6 months to 2 years) | Progressive strengthening and range work to rebuild full function, not just wait it out |
These timeframes vary widely, and stages overlap rather than switching cleanly, so treat this as orientation rather than a fixed prediction, and have a physiotherapist confirm your stage.
The injection and physiotherapy question
Physiotherapy and steroid injection are not competing options; the evidence increasingly supports combining them rather than choosing one over the other.
A frequent question we hear is whether an injection “fixes” a frozen shoulder on its own. It reliably reduces pain and inflammation, particularly in the freezing stage, but does not by itself restore lost range, because it does not reverse the capsular thickening. Physiotherapy targets that thickening through graded stretching and mobilisation, but progress is often slow if pain is not controlled first. In practice many people do best with an injection to bring pain down, followed immediately by structured physiotherapy to use that window to regain range. Where symptoms persist significantly beyond a year despite this combined approach, hydrodilatation (a capsule-stretching injection technique) or, less commonly, surgical capsular release are considered.
When home stretching plateaus: the loaded end-range approach
Gentle pendulum swings and passive stretches are a reasonable start, but frozen shoulder capsules generally respond better to sustained, loaded holds at end range than repeated brief stretches, which most generic advice pages leave out.
Rather than many short stretches, holding a comfortable end-range position (for example a doorway stretch or towel-assisted internal rotation stretch) for 30 to 60 seconds, repeated several times, encourages the capsule tissue to gradually remodel and lengthen. This should stay within a “stretch, not sharp pain” sensation; going too hard too early tends to provoke the inflammatory response and set progress back. A physiotherapist adjusts direction, hold time and technique to whichever movement is most restricted for you, since capsular tightness is rarely even across all directions.
What the evidence actually says
The research on frozen shoulder supports active, structured management over simply waiting it out, though the evidence on which specific treatment sequence is best is genuinely mixed.
Versus Arthritis, the UK charity focused on musculoskeletal conditions, describes frozen shoulder as usually resolving “in time” but notes this can take “as long as two to three years,” and sets out that hydrodilatation (steroid injection with saline stretching the capsule), physiotherapy, or steroid injection alone are the standard non-surgical pathway, with keyhole surgery reserved for cases that do not respond. A clinical guidelines review in PMC on the management of frozen shoulder puts conservative treatment success at up to 90% of patients, with surgery reserved for the minority whose symptoms do not settle after an extended course, typically six to nine months, of conservative care. Where evidence is more mixed is on manual therapy technique: some studies support high-grade mobilisation, others find gentler techniques equally effective paired with a home programme, so consistency of loading over months appears to matter more than the specific technique used session to session.
When to worry: red flags that need same-day care
Most shoulder stiffness and pain is safe to manage as frozen shoulder with physiotherapy, but a small number of presentations need same-day medical attention.
Seek same-day GP, NHS 24 on 111, or A&E assessment if shoulder pain comes with chest pain, breathlessness, or pain spreading to the jaw or left arm (possible cardiac cause, particularly important because immobility after a cardiac event is itself linked to frozen shoulder), sudden weakness or numbness in the arm or hand alongside facial drooping or speech changes (possible stroke), a fever with a hot, swollen, or red shoulder (possible joint infection, which needs urgent treatment), or a shoulder that became painful and unstable after a fall or direct injury with visible deformity (possible fracture or dislocation rather than frozen shoulder). NHS Inform Scotland’s guidance on frozen shoulder sets out this same distinction between routine and urgent presentations; if a red flag applies, treat it as urgent rather than booking a routine physiotherapy assessment.
Assessment and rehabilitation at our Davidsons Mains clinic
A first shoulder assessment at our Davidsons Mains clinic runs to a full hour, enough time to confirm the capsular pattern, rule out rotator cuff and cervical spine contributors, and agree a stage-appropriate plan rather than a generic stretching sheet.
We see a steady flow of frozen shoulder patients from Blackhall, Drylaw, Corstorphine and further across Edinburgh, many of whom have already tried general stretches without much change, usually because the stretches were not held at end range long enough or matched to their specific restricted direction. Our physio-led Pilates classes are a useful adjunct for people in the thawing stage, supporting scapular control as range returns, and our massage therapy service helps manage the compensatory neck and upper back tightness that builds when one arm has been guarded for months.
Common questions
How long does frozen shoulder usually last?
The full course typically runs from several months to two to three years across the freezing, frozen and thawing stages, though most people see meaningful improvement well before the endpoint, particularly with active treatment rather than waiting alone.
Does frozen shoulder go away on its own?
It usually resolves eventually without surgery, but “resolves” does not always mean a full return to pre-injury range for everyone, and the process is typically faster and less disabling with structured physiotherapy and, where appropriate, an injection, than with rest alone.
Is frozen shoulder the same as a rotator cuff tear?
No. A rotator cuff tear involves damage to specific tendons and usually causes weakness with a more selective loss of movement, while frozen shoulder involves the whole joint capsule tightening and typically restricts movement in a broader, more even pattern, especially rotation. An assessment differentiates the two, since the treatment approach differs.
Can I keep exercising with a frozen shoulder?
Generally yes, within comfortable range. Avoid forcing movement into sharp pain, but gentle, consistent range-of-motion work and lower-body or seated cardiovascular exercise are usually fine and help avoid the deconditioning that comes with fully avoiding the arm.
Will an injection cure my frozen shoulder?
An injection reduces pain and inflammation effectively, particularly in the early freezing stage, but it does not on its own reverse the capsule thickening that causes stiffness. It works best combined with a structured physiotherapy programme rather than as a stand-alone fix.
Why is my frozen shoulder worse at night?
Lying down changes the pressure and position around an already tight, sensitised capsule, and there are fewer daytime distractions from the discomfort. A physiotherapist can suggest sleep positioning and pillow support to reduce night pain while the underlying stiffness is being treated.
About the author
This article was written and clinically reviewed by the ProMOTION Physiotherapy Clinical Team, Chartered Physiotherapists (CSP) and HCPC registered, with backgrounds spanning NHS musculoskeletal services, elite sport, and private practice. Read more about the team on our practitioner page.
Book your shoulder assessment
If your shoulder is stiffening, painful at night, or not responding to home stretches, book online for an assessment at our Davidsons Mains clinic, or call 0131 538 5467. We see patients from across Edinburgh, including Blackhall, Drylaw, Corstorphine, Cramond and Silverknowes.
