If you have ever had a frozen shoulder, or watched someone you love struggle with one, you will know how frustrating it can be. The pain arrives, the movement disappears, and for a long time nobody can quite tell you why. At JSSC we see this condition regularly, and a large new review of the research has just given us a much clearer picture of what is going on beneath the surface.
A Condition We Are Still Getting to Know
Frozen shoulder, sometimes called adhesive capsulitis, causes the tissue around the shoulder joint to become inflamed and increasingly stiff. It can leave people unable to reach a shelf, fasten a seatbelt or sleep on one side, often for many months. For years the answer to “why has this happened to me” has largely been that we were not entirely sure. This new analysis, which pooled data from thousands of patients across many studies, takes a real step towards an answer.
What Is Actually Happening in the Shoulder
The lining of the shoulder joint, called the capsule, is normally a loose and elastic structure. That looseness is what gives the shoulder its huge range of movement, far more than any other joint in the body. With frozen shoulder, this capsule and its surrounding ligaments become inflamed, swollen and tight. The elasticity is lost, and pain and stiffness take its place. Clinically, we describe it as restricted movement in every direction, whether you are trying to lift the arm, reach across the body or rotate it, which is part of what sets it apart from other shoulder problems.
Frozen shoulder tends to fall into one of two groups. Primary frozen shoulder appears without an obvious trigger, though it is often linked to diabetes or the metabolic factors we describe below. Secondary frozen shoulder tends to follow an injury, surgery, or another medical cause. It is also seen more often in people who have Dupuytren’s contracture, a condition affecting the tissue in the hands, along with links to high cholesterol and heart disease. None of this means these conditions cause frozen shoulder outright, but it does point to a shared thread running through them, which the research we discuss below helps to explain.
It typically affects between two and five in every hundred people, and that figure climbs noticeably in people with diabetes, thyroid disorders or autoimmune conditions. It is also more common in women between the ages of forty and sixty five, particularly through the peri-menopausal and post-menopausal years, a pattern that has had surprisingly little research attention until recently.
Why Menopause Seems to Raise the Risk of a Frozen Shoulder
One of the more interesting threads in recent thinking is the possible role of oestrogen. Oestrogen does far more in the body than regulate the reproductive cycle. It also helps calm inflammation, supports tissue repair, and keeps connective tissue healthy and supple, including the capsule around the shoulder joint. As oestrogen levels fall and fluctuate through perimenopause and menopause, these protective effects reduce. The result can be an environment in the body that makes tissue more prone to inflammation, slower to heal, and more likely to thicken and stiffen, which may help explain why frozen shoulder shows up so much more often in women at this stage of life.
There also seems to be more to it than falling oestrogen alone. Some researchers think the body’s tissues can become less responsive to the oestrogen that is still there, particularly during the unpredictable hormonal swings of perimenopause, which may add to the same inflammatory, stiffening effect. It is worth saying that not every postmenopausal woman develops frozen shoulder, and it does happen in premenopausal women and in men too, so hormones are clearly only part of a bigger picture that also includes the metabolic and inflammatory factors described below, alongside lifestyle factors such as stress and activity levels. What this does suggest is that frozen shoulder is best understood as a whole body condition rather than a problem confined to the joint itself, which is exactly why we like to look at the wider picture with our patients rather than the shoulder in isolation.
The Body’s Chemistry Seems to Matter
The researchers looked closely at blood markers in people with frozen shoulder compared with those without it, and a pattern emerged. Long term blood sugar control, measured through a marker called HbA1c, was noticeably higher in people with frozen shoulder. Cholesterol levels told a similar story. Interestingly, short term blood sugar swings did not show the same link, which suggests it is the slow, steady picture of someone’s metabolic health that matters more than any single reading.
This will not surprise many of our patients, since frozen shoulder has long been recognised as more common in people with diabetes. What is new here is the strength of the evidence and the suggestion that broader metabolic health, not just diabetes itself, may play a part.
Inflammation Behind the Stiffness
The review also looked at the body’s inflammatory response, and two markers stood out. Both pointed towards an active inflammatory process driving the thickening and tightening of the shoulder capsule that causes the classic stiffness of this condition. This fits with what we feel clinically. Frozen shoulder rarely behaves like a simple mechanical problem. It behaves like the tissue itself is caught up in a slow, stubborn inflammatory process, which is part of why it can take so long to settle.
Not every marker told a consistent story. Triglycerides and one of the interleukins varied so widely between studies that no firm conclusion could be drawn, and thyroid function showed no clear link at all. The researchers are honest about this, and it is a helpful reminder that frozen shoulder is unlikely to have one single cause. It looks increasingly like a condition sitting at the crossroads of metabolic health and the immune system.
The Three Stages of Frozen Shouler, and Why Patience Matters
Frozen shoulder usually moves through three stages, though the timing varies a great deal from person to person. It can start out of nowhere, or be set off by a minor knock to the shoulder. The first stage, freezing, is dominated by pain, often before stiffness has properly set in, which means it can initially be mistaken for a more straightforward shoulder strain. The second stage, frozen, brings some relief from the pain but the stiffness remains, sometimes for months. The third stage, thawing, is when movement gradually returns.
Left untreated, most frozen shoulders do ease on their own, but this can take anywhere from eighteen months to two years, and sometimes longer. That is a long time to live with pain and restriction, which is why most people choose not to simply wait it out.
Why a Physiotherapist Is Often Your First Port of Call
Frozen shoulder can be tricky to identify in its early stages, since the pain often mimics other shoulder problems before the stiffness sets in. A physiotherapist at the JSSC is well placed to tell the difference. Through a thorough history and a hands on examination, checking how the shoulder moves both actively and when we move it for you, we can usually recognise the pattern of a true frozen shoulder with confidence, and just as importantly, rule out other causes of shoulder pain that need a different approach entirely. Where there is any doubt, or a suggestion of something else going on, we will refer you on for imaging or a specialist opinion, working alongside your GP or an orthopaedic consultant as needed.
That role does not stop at diagnosis. A physiotherapist is usually the professional guiding you through the whole course of the condition, from the first painful weeks through to the final return of movement, adjusting the approach as you move between stages and helping you judge when other options, such as an injection or a surgical opinion, might be worth exploring.
Getting the Right Support Along the Way
The right approach depends on how much pain you are in and how stiff the shoulder has become, and it often changes as you move through the three stages. Physiotherapy sits at the centre of managing frozen shoulder throughout, helping to protect the range of movement you still have, guiding pain relief and activity choices in the early painful stage, and gently working to regain what has been lost as things ease. Anti-inflammatory medication can help alongside this in the more painful early stage. For some people, an injection into the joint reduces inflammation and eases pain enough to make progress with movement possible, and a physiotherapist can help you weigh up whether this is worth considering.
When pain and stiffness are more severe or slow to settle, a procedure called hydrodilatation, which gently stretches the capsule using fluid injected into the joint, can be more effective than an injection alone, and again tends to work best when paired with physiotherapy rather than used on its own. Shockwave therapy is another option that has gained ground more recently, and can be particularly useful for people with diabetes, since it avoids the small metabolic effects that steroid injections can sometimes carry. In cases that do not settle after six to twelve months of these measures, surgery is an option, most commonly a capsular release to free up the tightened tissue, or manipulation of the shoulder under anaesthetic.
The strongest evidence we have on how these options compare comes from the UK FROST trial, a large national study of over five hundred patients across thirty five hospitals, which compared early structured physiotherapy with a steroid injection against both manipulation under anaesthetic and arthroscopic capsular release. The finding was reassuring for anyone hoping to avoid surgery. At twelve months, outcomes were broadly similar across all three approaches, with only a marginal edge for capsular release. Physiotherapy could be started soonest and cost the least, though a few more patients went on to need further treatment. Manipulation proved the most cost effective option overall, while capsular release carried higher risks and costs but slightly fewer people needed anything further afterwards. Taken together, this points towards early structured physiotherapy as a genuinely sound first choice for most people, with surgery kept in reserve for cases that do not settle with less invasive care.
Whichever route is needed, physiotherapy rehabilitation afterwards is essential to protect and build on the improved movement, and is usually what determines how well the result is maintained in the months that follow. Whatever stage you are at, the aim is the same: keeping you as comfortable and mobile as possible while your shoulder works through its natural course, with your physiotherapist coordinating that care alongside you.
Simple Things You Can Do Yourself
Alongside professional treatment, there is a good deal you can do day to day to support your shoulder. Try to keep the joint moving within a comfortable range rather than avoiding it altogether, since prolonged rest tends to add to the stiffness rather than easing it. Gentle stretches, guided by your physiotherapist so they suit the stage you are at, help maintain what movement you have. Managing stress where you can also seems to help, alongside general activity and movement, given the wider role the body’s inflammatory and hormonal state appears to play. Above all, if you notice stiffness building, night pain, or a gradual loss of movement, it is worth seeking advice early rather than waiting, since earlier support tends to make the whole course of the condition more manageable.
What This Means for You
We are not sharing this to worry anyone, but because understanding why something is happening tends to make it far easier to manage. If you are living with frozen shoulder, or notice stiffness developing, it is worth mentioning your general health picture to us, including things like cholesterol and blood sugar, alongside the shoulder itself. This is exactly the kind of joined up, whole person approach we believe in at JSSC. Working in partnership with you, your GP and other specialists where needed, rather than looking at the shoulder in isolation.
The good news is that frozen shoulder does resolve, even without this new research. The right treatment plan, built around your goals and your body, still makes a real difference to how comfortable that journey is and how quickly you get moving again, and it is your physiotherapist who tends to hold that plan together from diagnosis through to full rehabilitation. As our team continues to learn from research like this, we are able to bring that fuller picture into the room with you.
It Is Not Just a Physical Struggle
It is worth saying something about the emotional side of frozen shoulder too, because it is rarely just about the shoulder itself. A recent study interviewed people who had experienced frozen shoulder and had a corticosteroid injection as part of their care, and the findings will feel familiar to many of our patients. People often described wanting an injection quite urgently, sometimes without dwelling too much on the possible risks, simply because the pain and disruption to daily life had become so hard to bear. The study also picked up on something we hear often in clinic, which is confusion and frustration at not understanding why frozen shoulder had happened, and for some people a sense that it was a marker of getting older, which affected how they felt about their body and themselves more broadly. It also touched on how the condition ripples outward to affect family, work and relationships, not just the person carrying the pain.
We share this because it is a reminder that good care for frozen shoulder is about more than choosing the right treatment. It is about being heard, having your questions about causes and risks properly answered, and being supported through what can be a properly difficult and drawn out experience. That person centred approach sits at the heart of how we work at JSSC.
If you are dealing with shoulder pain and stiffness, or simply want it looked at properly, our physiotherapists would be glad to help. Call us on 01534 490312 or book online to arrange an assessment.
*References: Systematic review and meta-analysis of metabolic and inflammatory biomarkers in frozen shoulder, pooling data from 7,499 individuals and 28,416 blood samples. Bilsborough Smith et al., Living with frozen shoulder. ‘Here are the risks. I want the injection.’ An interpretative phenomenological analysis, Musculoskeletal Science and Practice, 2023. Rangan et al., Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial, The Lancet, 2020.*