Broken arm or wrist

The arm breaks more often than any other part of the body, and almost always in the same way: someone falls and puts a hand out at the last moment. Most of the force lands on the radius just above the wrist, which makes this the commonest fracture in adults. Less often the small bones of the hand, the elbow or the upper arm bone give way. Telling a fracture from a bad sprain on the spot is usually impossible; the X-ray decides. Hence a simple rule: after a significant arm injury it is better to go and be told the bone is intact than to spend a week walking around with a fracture nobody has spotted.

Telling a break from a bad bruise

There is no reliable home test, but some signs make a fracture much more likely:

• the pain started at once, does not settle at rest, and you cannot put any weight through the arm;
• swelling builds within minutes rather than over several hours;
• the outline of the arm has changed: there is a step, a bend or an odd angle;
• you cannot turn the hand or forearm palm up and palm down;
• pressing produces pain at one precise point on the bone rather than spread through the soft tissue.

Misleading cases are common too. A crack without displacement hurts only moderately, the arm still moves, the bruise appears on the second day, and the injury gets written off as a knock. In older people and in children a bone can break in a fall from standing height, and sometimes with no fall at all: if the fracture happened during ordinary activity, it is worth discussing bone strength with a doctor separately.

When you need emergency care

Go to an emergency department without waiting until morning if any of the following apply:

• bone is visible in a wound, or the wound sits directly over the break;
• the arm or wrist is clearly deformed, or the hand hangs at an unnatural angle;
• the fingers are numb, pale or cold, or have stopped moving;
• bleeding does not stop with pressure;
• pain is escalating fast and is out of all proportion to how the injury looks.

Do not drive yourself. Ask someone to take you, or call the emergency number, 112. On the way, do not eat or drink anything: if a general anaesthetic turns out to be needed, a full stomach will delay the operation. Take a list of the medicines you use regularly, and tell the doctor straight away if any of them thin the blood.

The scaphoid: the fracture that is missed most often

This one is worth knowing about in advance, because the cost of missing it is high. The scaphoid is a small wrist bone at the base of the thumb. It breaks in exactly the same fall onto an outstretched hand, but it behaves deceptively: the arm is not deformed, swelling is slight, and the person carries on using the hand, sure they have only pulled a ligament.

There is one suspicious sign: tenderness in the small hollow at the base of the thumb, which shows up when the thumb is moved out to the side. Pain on gripping hard or on pinching adds to the picture.

The main difficulty is that in the first few days a fresh scaphoid fracture often does not appear on X-ray at all. A normal film proves nothing here. So when the pain is typical, the wrist is splinted and the X-ray repeated after one or two weeks, or a CT or MRI scan is arranged straight away.

This bone receives its blood supply from one end only, and a fracture easily cuts that supply off. A missed scaphoid fracture heals badly, and part of the bone can die: the result is long-term pain and early arthritis of the wrist, which by then needs surgery. If an injured wrist is still painful after two weeks, go back to the doctor and say this suspicion out loud.

What to do while you get to a doctor

First aid here has a modest job: reduce swelling and do no harm.

• take rings, bracelets and a watch off the injured arm in the first few minutes, before swelling makes it impossible;
• support the arm in a scarf or folded cloth so the forearm lies level and the hand sits a little higher than the elbow;
• apply something cold wrapped in fabric for 15–20 minutes and repeat every two or three hours; never put ice straight onto skin;
• cover any wound with a clean dressing and control bleeding by pressing over the top of it;
• paracetamol is a reasonable painkiller; ask a doctor about anti-inflammatory ones.

What not to do: try to straighten the arm yourself, "work it loose", test how far it will move, or wrap it tightly in an elastic bandage. If bone is sticking out of a wound, leave it alone and do not push it back in; simply cover it with a sterile cloth.

What happens at the hospital

Staff start with examination and pain relief, then take X-rays in two views. The films show whether there is a fracture, whether the fragments have separated and whether the break runs into a joint, and everything else follows from that.

If the fragments have shifted, they are put back into position. This is done by hand under local anaesthetic or brief sedation, and the arm is immobilised in plaster or a synthetic cast immediately afterwards. Sometimes the arm is kept in an open splint for the first few days and the full cast applied later, once the swelling has gone down, so that the cast does not press on the tissues.

Surgery is not always needed, but it is not rare either: it is considered for open fractures, breaks that run into a joint, fractures in several pieces, and cases where the fragments will not stay in place. The bone is held with a plate and screws, with wires, or with a rod inside the bone.

You go home with painkillers and a date for a check X-ray. That check is not a formality: fragments can slip inside the cast during the first or second week, and only an X-ray will show it.

The cast, recovery, and what should worry you

A wrist cast usually stays on for four to six weeks; forearm and upper arm fractures take longer. Full recovery takes around two to three months, and stretches to six when a joint is involved or the person is elderly.

While the arm is in a cast, keep it raised, prop it on a pillow at night, and move the fingers and shoulder every hour: nothing works better against swelling and stiffness. The cast must stay dry, and pharmacies sell waterproof covers for showering. Never push anything under the cast to scratch: a scratch under plaster infects easily, and a knitting needle cannot be retrieved once it is down there.

See a doctor immediately if the pain under the cast is not easing but growing day by day, if the fingers swell, turn blue or pale, lose sensation, or if there is burning or a feeling of unbearable tightness. That is how tissue compression inside an unyielding space shows itself, whether the space is the cast or the body's own fascia. Without prompt treatment it ends in muscle death and permanent loss of hand function, so waiting until morning or until a scheduled appointment is not an option. Sudden severe forearm pain under a tight bandage deserves the same urgency, even with no cast on.

Once the cast comes off the arm looks strange: thinner, weaker, stiff, with flaking skin. That is normal and it reverses. Stiffness eases with the daily exercises a doctor or physiotherapist gives you, and strength is the last thing to return, over months. Do not force loading through pain and do not start with weights: range of movement first, strength afterwards.

Online consultation

An online appointment does not replace an X-ray, but it does help you avoid both wasted time and lost time. The doctor will go through exactly how the injury happened and judge, from your description and a photograph, how likely a fracture is and whether you should head to an emergency department right now. If the X-ray is already done, they can help you make sense of the report and know what to expect. It is also worth getting in touch if the arm still hurts more than two weeks after the injury, if the cast feels too tight or has worked loose, or if movement is not coming back after it is removed: the doctor can say which exercises are safe and when an in-person review is needed.

This material is for information only and does not replace medical advice.