Frozen shoulder, also known as adhesive capsulitis, is a common, painful condition that affects the ability to move the shoulder.

Frozen shoulder reduces normal movement in the joint and, in some cases, it can prevent movement in the shoulder altogether.

Pain and stiffness in the shoulder are the most common symptoms of a frozen shoulder..

How common is frozen shoulder?

Most cases of frozen shoulder occur in people between the ages of 40 and 60. The condition is more common in women than men. It is estimated that a frozen shoulder could affect up to 1 in 20 people.

The exact cause of frozen shoulder is not fully understood, although it appears to be more common in people with certain health conditions, such as diabetes (a long-term condition that is caused by too much glucose in the blood).

Outlook

There are several different forms of treatment for frozen shoulder, including:

• painkillers
• physiotherapy, where physical methods are used to promote healing
• surgery

Recovery from a frozen shoulder can be slow and the symptoms can last for several years. However, most people with the condition eventually regain full movement in their shoulder.

If you have frozen shoulder, only one shoulder will usually be affected, although the condition can sometimes spread to the other shoulder. A frozen shoulder is not related to arthritis and other joints are not affected.

A frozen shoulder is a painful, persistent stiffness of the shoulder joint, which makes it very difficult to carry out the full range of normal shoulder movements.

You may find it difficult to carry out everyday tasks, such as:

• dressing
• driving
• sleeping comfortably

Some people find they are unable to move their shoulder at all, which is why the condition is known as a frozen shoulder.

Stages of frozen shoulder

The symptoms of a frozen shoulder advance slowly and are usually experienced in three separate stages that are spread over a number of months or years. However, the symptoms of frozen shoulder can vary greatly from person to person.

The three stages of frozen shoulder are described below.

Stage one

During stage one, your shoulder will start to ache and will feel stiff before becoming very painful. The pain is often worse at night and when you lie on the affected side. This stage lasts two to nine months.

Stage two

Stage two is known as the adhesive stage. Your shoulder may become increasingly stiff, but the pain will not usually get worse. Your shoulder muscles may start to waste slightly because they are not being used. This stage lasts four to twelve months.

Stage three

Stage three is the recovery stage. During this stage, you will gradually regain movement in your shoulder. The pain will begin to fade, although it may recur from time to time as the stiffness eases.

Although you may not regain full movement of your shoulder, you will be able to do many more tasks. Stage three can last five months to three or four years.

A frozen shoulder occurs when there is thickening and swelling of the flexible tissue that surrounds your shoulder joint. This tissue is known as a capsule.

Your shoulder is a ball and socket joint, in which the end of your upper arm bone (humerus) sits in the socket of your shoulder blade (scapula). The shoulder capsule is fully stretched when your arm is raised above your head, and hangs down as a small pouch when your arm is lowered.

In cases of frozen shoulder, it is thought that bands of scar tissue form inside the shoulder capsule, causing it to thicken, swell and tighten. This leaves less space for your upper arm bone in the joint and makes any movement stiff and painful.

Risk factors

The reason why a frozen shoulder occurs is not fully understood. In some cases, it may not be possible to identify a cause. However, there are several risk factors that make developing a frozen shoulder more likely.

Shoulder injury or surgery

It is possible to develop a frozen shoulder following a shoulder or arm injury, such as a broken bone (fracture) or after having surgery to your shoulder area.

This may be because keeping your arm and shoulder immobile (still) for long periods of time during your recovery may cause your shoulder capsule to tighten up from lack of use. For this reason, it is important not to ignore a painful injury to your shoulder area and to always visit your GP.

Diabetes

If you have diabetes (a long-term condition caused by too much glucose in the blood), you are more likely to develop a frozen shoulder. The exact reason for this is unknown. If you have diabetes, you are also more likely to:

• develop the condition in both your shoulders
• have more severe symptoms

It is estimated that around a third of people with diabetes have a frozen shoulder.

Other health conditions

Your risk of developing a frozen shoulder may also be increased by having other health conditions including:

• heart disease, where the heart’s blood supply is blocked or interrupted
• lung disease, which affects your airways
• an overactive thyroid gland (hyperthyroidism), where the thyroid gland, which is found in your neck, produces too many hormones (powerful chemicals)
• Parkinson's disease, a chronic (long-term) condition that affects the way the brain co-ordinates body movements, including walking, talking and writing
• a stroke, when the blood supply to the brain is disturbed or interrupted
• Dupuytren's contracture, a condition that causes your fingers to bend into the palm of your hand due to the thickening and shortening of the tissue in your palm

Immobility

Being immobile (not moving) for a long period of time is also a risk factor for frozen shoulder. This can occur if you are in hospital, for example after having a stroke or car accident.

See your GP if you think that you may have a frozen shoulder, or if you have shoulder pain that limits your range of movement. Early treatment of a frozen shoulder can help prevent long-term stiffness and pain in your joint.

Your GP will ask you about your symptoms and carry out a physical examination of your shoulder area.

Symptoms

Your GP will want to know:

• when your symptoms started, particularly if this was after an incident, such as a fall
• if anything makes the pain better or worse, such as movement or resting
• how severe the pain is
• if you have any other symptoms, such as neck pain
• how your symptoms affect your everyday life, for example your job
• if you have any other health conditions or if you are taking any medication

Physical examination

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 also assist you in moving your arm and shoulder. Although this may be painful, it will help them to determine how severe your condition is.

Your GP may also apply pressure to parts of your shoulder to determine where your pain is most severe and what is causing it.

They will also look for:

• swelling
• bruising
• muscle wasting

Further tests

You may need to have further tests to rule out other conditions. For example, you may have a blood test if your GP thinks you may have:

• diabetes (a long-term condition that is caused by too much glucose in the blood). Frozen shoulder is more common in people with diabetes
• polymyalgia rheumatica, a condition that causes the tissues of the joints to become inflamed (red and swollen), causing symptoms such as muscle pain and stiffness

Your GP will also rule out other possible causes of your symptoms, such as:

• infection
• a tumour (growth)

Imaging

If the inside of your shoulder joint needs to be examined to rule out other damage, an image of your shoulder may be taken. However, this is rarely necessary to confirm your diagnosis. If an image is required, you may have:

• an X-ray, where high-energy radiation is used to show up abnormalities in bones and certain body tissue
• a magnetic resonance imaging (MRI) scan, where a strong magnetic field and radio waves are used to produce detailed images of the inside of your body

Treatment for a frozen shoulder varies depending on the stage of the condition and the severity of your pain and stiffness. The aim of treatment is to keep your joint as mobile and pain free as possible while your shoulder heals.

A frozen shoulder usually resolves itself over a period of 18 to 24 months. While treatment will not necessarily speed up your recovery, it can make it more bearable.

Early stage

The early stage of a frozen shoulder is the most painful stage.

If you are in the early stage of frozen shoulder, your GP may recommend that you avoid movements that make the pain worse, such as stretching overhead. However, do not stop moving altogether.

Treatment during this stage is mainly focussed on relieving the pain.

Painkillers

If you are in pain, you may be prescribed painkillers, such as paracetamol, or a combination of paracetamol and codeine. Some painkillers, such as paracetamol, are also available over-the-counter (OTC) in pharmacies. Always follow the manufacturer’s instructions to ensure that the medication is suitable for you, and that you are taking the correct dose.

If your pain is more severe, your GP may recommend or prescribe a non-steroidal anti-inflammatory drug (NSAID). As well as easing pain, NSAIDs will help reduce the swelling in your shoulder capsule. NSAIDs are most effective when taken regularly, rather than as and when the symptoms are most painful.

There are some side effects associated with NSAIDs. See the patient information leaflet that comes with your medication for more information about the possible side effects.

Do not take NSAIDs if you have:

• asthma (a condition that affects the lungs)
• high blood pressure (hypertension)
• kidney or heart problems

Corticosteroid injections

If you have a severe case of frozen shoulder, treatment using painkillers may not be enough to control the pain. If this is the case, you may be able to have corticosteroids injected into and around your shoulder joint.

Corticosteroids are medicines that contain hormones (groups of powerful chemicals that have a wide range of effects on the body). They help to reduce swelling and pain. Corticosteroids may also be given with local anaesthetic (painkilling medication).

Corticosteroid injections can help relieve pain and improve the movement in your shoulder. However, the injections cannot cure your condition and your symptoms will gradually return. Corticosteroid injections will also not be used once the pain has faded from your shoulder and only the stiffness remains.

Too many corticosteroid injections can cause damage to your shoulder, so you may only be able to have this type of treatment up to three times in one year. You will need at least three to four weeks between injections.

Later stages

After the initial, painful stage, stiffness is the main symptom of a frozen shoulder. At this time, your GP may suggest that you start doing shoulder exercises, and they may refer you for specialist treatment from a physiotherapist (a healthcare professional who is trained in the use of physical methods, such as massage and manipulation, to promote healing).

Shoulder exercises

If you have a frozen shoulder, it is important to keep your shoulder joint mobile with regular, gentle exercise. Not using your shoulder can cause your muscles to waste and may make stiffness worse. Therefore, if you can, continue to use your shoulder as normal.

However, if your shoulder is very stiff, exercise may be painful. Your GP or physiotherapist can give you exercises that you can do without further damaging your shoulder.

Physiotherapy

If you are referred to a physiotherapist, they will help you maintain movement and flexibility in your shoulder using a number of techniques. You may have treatments such as:

• massage
• thermotherapy with warm or cold temperature packs
• transcutaneous electrical nerve stimulation (TENS, see below)

Shiatsu massage is also becoming increasingly popular as a complementary physiotherapy for frozen shoulder. However, there is no clinical evidence to prove its effectiveness.

Transcutaneous electrical nerve stimulation (TENS)

Transcutaneous electrical nerve stimulation (TENS) is a type of physiotherapy that may help ease the pain of frozen shoulder. It numbs the nerve endings in your spinal cord that control pain, so that you can no longer feel it.

Treatment with TENS is usually given by a physiotherapist. Small electrical pads (electrodes) will be applied to the skin over your shoulder. These will deliver small pulses of electricity from the TENS machine. Your physiotherapist can control the strength of the pulses and how long they last.

Alternative therapies

Some alternative therapies, such as acupuncture (a treatment that involves inserting fine needles into your skin at certain points on the body) claim to relieve or prevent the symptoms of a frozen shoulder.

However, the lack of evidence supporting their effectiveness means that more research is needed before they can be recommended.

If you decide to use herbal remedies, check with your GP first because some remedies, such as St John’s Wort, can react unpredictably with other medication or make it less effective.

Surgery

Surgery for frozen shoulder is rarely necessary, but you may be referred for surgery if other treatments have not worked after six months. You could be referred to:

• an orthopaedic surgeon, who specialises in conditions that affect the bones and muscles
• a rheumatologist, who specialises in conditions that affect the muscles and joints

There are two possible surgical procedures, which are explained in more detail below.

Manipulation

You can have your shoulder manipulated (moved) while you are under general anaesthetic (a painkilling medication that makes you unconscious). During this procedure, your shoulder is gently moved and stretched while you are asleep.

Afterwards, you will usually require physiotherapy to help maintain mobility in your shoulder. Manipulation may be used if you are finding the pain and disability from your shoulder difficult to cope with.

Arthroscopic capsular release

An alternative procedure to manipulation is arthroscopic capsular release. This is a type of keyhole or non-invasive surgery. The surgeon will carry out the procedure after making an incision (cut) that is less than 1cm (0.4in) long.

During arthroscopic capsular release surgery, your surgeon will use a special probe to open up your contracted shoulder capsule. They will then remove any bands of scar tissue that have formed in your shoulder capsule, which should greatly improve your symptoms.

As with manipulation, you will need to have physiotherapy after arthroscopic capsular release surgery. This is to help you regain a full range of movement in your shoulder joint

If you have pain in your shoulder that limits your range of movement, it is important to see your GP. Early treatment of frozen shoulder can help to prevent long-term stiffness in the joint. Make sure you gently stretch the shoulder before exercising, and try to maintain good posture.