Frozen shoulder is a condition that leads to pain and stiffness of the shoulder. It's also known as adhesive capsulitis or shoulder contracture.
The symptoms tend to gradually get worse over a number of months or years. You'll typically experience shoulder pain for the first two to nine months, which can be severe, followed by increasing stiffness.
The stiffness may affect your ability to carry out everyday activities. In particularly severe cases, you may not be able to move your shoulder at all.
The condition may improve with time, but this can sometimes take several years.
It's estimated that up to 1 in 20 people in the UK may be affected by frozen shoulder at some point in their life. Most people who get frozen shoulder are between the ages of 40 and 60. The condition is more common in women than men.
Pain and persistent stiffness in the shoulder joint are the two main symptoms of a frozen shoulder.
This makes it painful and difficult to carry out the full range of normal shoulder movements. You may find it difficult to perform everyday tasks, such as:
Symptoms vary from mild, with little difference to daily activities, to severe, where it may not be possible to move your shoulder at all.
You should see your GP if you think you have a frozen shoulder, or if you have persistent shoulder pain that limits your movement.
Stages of frozen shoulder
The symptoms of a frozen shoulder usually get worse gradually, over a number of months or years.
There are three separate stages to the condition (see below), but sometimes these stages may be difficult to distinguish. The symptoms may also vary greatly from person to person.
During stage one, often referred to as the "freezing" phase, your shoulder starts to ache and become very painful when reaching out for things.
The pain is often worse at night and when you lie on the affected side. This stage can last anywhere from two to nine months.
Stage two is often known as the "frozen" phase. Your shoulder may become increasingly stiff, but the pain doesn't usually get worse and may even decrease.
Your shoulder muscles may start to waste away slightly because they're not being used. This stage usually lasts 4-12 months.
Stage three is the "thawing" phase. During this period, you'll gradually regain some movement in your shoulder. The pain begins to fade, although it may come back occasionally as the stiffness eases.
You may not regain full movement of your shoulder, but you'll be able to carry out many more tasks. Stage three can last from six months to many years.
Causes of frozen shoulder
Frozen shoulder occurs when the sleeve that surrounds the shoulder joint, known as the capsule, becomes swollen and thickened. It's unclear why this happens.
The shoulder is a ball and socket joint. The end of your upper arm bone (humerus) sits in contact with the socket of your shoulder blade (scapula).
The shoulder capsule is fully stretched when you raise your arm above your head, and hangs down as a small pouch when your arm is lowered.
In frozen shoulder, bands of scar tissue form inside the shoulder capsule, causing it to thicken, swell and tighten. This means there's less space for your upper arm bone in the joint, which limits movements.
Who's most at risk?
It's not fully understood why frozen shoulder occurs, and it's not always possible to identify a cause. However, a number of factors can increase your risk of developing it. These are outlined below.
Age and gender
Most people affected by frozen shoulder are aged between 40 and 60. The condition is more common in women than men.
Previous shoulder injury or surgery
Frozen shoulder can sometimes develop after a shoulder or arm injury, such as a fracture, or after having surgery to your shoulder area.
This may partly be a result of keeping your arm and shoulder still for long periods of time during your recovery. Your shoulder capsule may tighten up from lack of use.
Because of this, it's very important not to ignore a painful shoulder injury and to always seek medical advice.
If you have diabetes, you have a greater risk of developing a frozen shoulder. The exact reason for this is unknown.
It's estimated that people with diabetes are twice as likely to develop a frozen shoulder.
If you have diabetes, the symptoms of frozen shoulder are likely to be more severe and harder to treat. You're also more likely to develop the condition in both shoulders.
This means it's important to have your diabetes checked regularly to make sure it's controlled with the right medication.
Other health conditions
You may have a greater risk of developing a frozen shoulder if you have other health conditions, such as:
whether there's anything that makes the pain better or worse
if you have any other health conditions, or if you're taking any medication
During the physical examination, your GP may test your range of movement by asking you to move your arm and shoulder as far as you can in each direction.
Your GP may apply pressure to parts of your shoulder, to determine where your pain is most severe and what's causing it. They'll also look for any swelling, bruising or muscle wasting.
You may sometimes need to have further tests to rule out other possible health conditions.
For example, if your GP thinks you may have blood test may be recommended. Frozen shoulder is more common in people with diabetes.
An image of your shoulder joint may be taken to check for any physical signs that could suggest another cause of your symptoms. For example, wear and tear caused by arthritis, or a tear in the tendons around the shoulder.
This may involve:
an X-ray– to rule out other causes of stiffness in the shoulder, such as arthritis
If painkillers aren't helping to control the pain, it may be possible to have a corticosteroid injection in your shoulder joint.
Corticosteroids are medicines that help reduce pain and inflammation. They may also be given with a local anaesthetic.
These injections can help relieve pain and improve the movement in your shoulder. However, injections won't cure your condition and your symptoms may gradually return.
Corticosteroid injections won't be used after the pain has gone from your shoulder and only the stiffness remains.
Having too many corticosteroid injections may damage your shoulder, and the injections often become less effective over time, so your doctor may recommend having no more than three injections. You'll need at least three to four weeks between these.
After the initial painful stage, stiffness is the main symptom of a frozen shoulder. Your GP may suggest stretching exercises, and you may also be referred to a physiotherapist.
If you have a frozen shoulder, it's important to keep your shoulder joint mobile with regular, gentle stretching exercises. Not using your shoulder could make the stiffness worse, so you should continue to use it as normal.
However, if your shoulder is very stiff, exercise may be painful. Your GP or physiotherapist can give you some simple exercises to do every day at home that won't damage your shoulder any more.
A physiotherapist can use a number of techniques to keep the movement and flexibility in your shoulder. If you're referred to one, you may have treatments including:
stretching exercises that use specific techniques to move the joint in all directions
thermotherapy, with warm or cold temperature packs
There's no clinical evidence to show that certain other treatments are effective in treating frozen shoulder, including:
It's uncommon to need surgery for a frozen shoulder, but it may be recommended if your symptoms are severe and other treatments haven't worked after six months.
If this happens, you may be referred to an orthopaedic surgeon (a specialist in conditions that affect the bones and joints). Some of the procedures used to treat frozen shoulder are described below.
Manipulation under anaesthetic
If you're finding the pain and movement restriction difficult to cope with, you can have your shoulder manipulated (moved) while you're under general anaesthetic.
During this procedure, your shoulder will be moved, in a controlled way, to stretch the sleeve (shoulder capsule) surrounding the shoulder joint.
After the procedure you'll usually have corticosteroid and local anaesthetic injected into your shoulder joint to help reduce any pain or swelling.
You can normally go home the same day. Physiotherapy is usually recommended afterwards to help maintain mobility in your shoulder.
Arthroscopic capsular release
Arthroscopic capsular release is an alternative procedure to manipulation. It's a type of minimally invasive or "keyhole" surgery, carried out under general anaesthetic, where two or three small incisions are made around your shoulder.
The surgeon will insert a thin tube containing a light and camera (arthroscope) into one of the incisions, so they can see inside your shoulder. A special probe that emits high-frequency radio waves is inserted through the other incisions, and this is used to divide or cut out the thickened parts of the shoulder capsule. Opening up the shoulder capsule in this way should greatly improve your range of movement.
As with manipulation, you can usually go home the same day you have this operation, and you'll probably need physiotherapy afterwards to help you regain a full range of movement in your shoulder joint. Stretching exercises need to be continued for at least three months after surgery.
Shoulder stiffness may return, despite manipulation or surgery, and further treatment may be necessary.
Arthrographic distension (hydrodilatation)
Although it's less commonly performed than the operations described above, a procedure called arthrographic distension or hydrodilatation may sometimes be recommended to treat your frozen shoulder.
This treatment is carried out under local anaesthetic, which means you'll be awake while it's carried out, but your shoulder will be numbed.
It may be performed by a specialist orthopaedic surgeon using a local anaesthetic and corticosteroids, or saline with corticosteroids. X-ray guidance may sometimes be needed.
This procedure usually only takes about 15 minutes, and you can go home the same day. As with the other procedures described above, physiotherapy may be recommended afterwards to help you regain a good range of movement in your shoulder.
There's some evidence that hydrodilatation may result in less pain and greater movement, although the effects may be no better than a corticosteroid injection.