Frozen shoulder

What is frozen shoulder?

Frozen shoulder (also called adhesive capsulitis) happens when the capsule of tissue surrounding your shoulder joint becomes inflamed and thickened, causing pain and stiffness.

It develops gradually and can take months, or even a few years, to fully settle, though it usually improves on its own eventually.

Symptoms of frozen shoulder

The two main symptoms are pain and stiffness in your shoulder. Pain often starts gradually, tends to be worse at night, and can disturb your sleep, especially if you lie on the affected side. It's often worse when reaching for things or lifting your arm.

As the condition progresses, the shoulder becomes increasingly stiff, making it harder to carry out everyday tasks such as washing your hair, getting dressed, reaching behind your back, or drying yourself after a bath or shower.

Frozen shoulder often develops through three overlapping phases, though timings vary a lot from person to person.

• There's a painful phase, which can last from 2–9 months.
• This is followed by a stiffening phase, where pain eases but the shoulder becomes increasingly stiff.
• Finally a thawing phase, where movement gradually returns.

In total, it can take anywhere from 12–42 months to fully resolve, and some people are left with a small amount of permanent stiffness.

Causes and risk factors

It's often not clear why someone develops frozen shoulder. In most cases, there's no obvious trigger. In others, it follows a specific event, such as a shoulder injury or operation that meant you couldn't move your arm normally for a while, or it develops alongside a condition such as diabetes, though it isn't clear why this link exists.

You may be more likely to develop frozen shoulder if you:

• are aged 40 to 70
• have had a shoulder injury or surgery that stopped you moving your arm normally for a while
• have diabetes, a thyroid condition, or have had a stroke
• have already had frozen shoulder in your other shoulder – around one in 10 people go on to develop it in the other shoulder too, and this risk is higher if you have diabetes.

How is frozen shoulder diagnosed?

A GP, physiotherapist or specialist can usually diagnose frozen shoulder by asking about your symptoms and examining your shoulder, checking how far you can move it both on your own and with help.

An X-ray isn't usually needed, but one may be arranged to rule out other causes, such as osteoarthritis. With frozen shoulder, the X-ray itself usually looks normal.

How is frozen shoulder treated?

There's no single treatment that reliably cures frozen shoulder, but several options can help ease symptoms while it runs its course.

Non-surgical treatment

Treatment usually starts with simple pain relief and moving your shoulder gently rather than resting it completely, since keeping it moving within what your pain allows helps rather than harms it. 

Paracetamol is usually tried first, then an anti-inflammatory painkiller such as ibuprofen if needed. A heat pack wrapped in a towel, used for up to 20 minutes at a time, can also help. It's best to avoid making up your own strenuous exercises, such as using gym equipment, as this can make things worse.

If pain continues, you may be offered stronger painkillers or a steroid injection into the shoulder, though this is usually only continued short-term because of side effects, and the benefit can be unpredictable and short-lived, sometimes needing a repeat injection. A physiotherapist can also guide you through stretching and strengthening exercises, usually over a course of at least 6 weeks, alongside posture advice.

If symptoms persist, other injection-based options include a steroid injection targeted at a specific nerve at the back of the shoulder to block pain signals, or hydrodistension (also called a distension arthrogram), where fluid is injected into the joint under imaging guidance to help stretch the capsule.

Surgical treatment

Surgery is rarely needed and is generally only considered if severe symptoms persist despite other treatments. Manipulation under anaesthesia involves moving your arm while you're asleep to help loosen the tight capsule. Arthroscopic capsular release is keyhole surgery where a surgeon uses a camera to guide the cutting of the thickened capsule to improve movement.

Risks of surgery include infection, nerve injury, bleeding, and, rarely, a fracture of the arm bone, alongside the usual risks of a general anaesthetic, which are higher if you have other significant health conditions.

When should I see a doctor?

See a GP if you have shoulder pain and stiffness that isn't improving, or if the pain is bad enough to make it hard to move your arm or shoulder. If you've been managing your symptoms yourself and haven't improved within 6–12 weeks, ask about a referral to a physiotherapist.

Get urgent medical advice if you have extreme pain, you can't move your arm at all after a fall or injury, you have pins and needles or numbness in your arm, the skin over your shoulder is hot, red or swollen, you feel feverish or unusually unwell, or you have unexplained weight loss or night sweats, since these can be signs of something other than frozen shoulder that needs prompt attention.