Ankle pain and sprain: causes, red flags and when to seek help

The ankle is a hinge joint held together by ligaments, with tendons running past it to the foot and several bones meeting at its core. Most people who search for ankle pain have just rolled the foot inwards while walking, running or stepping off a kerb. The ligament on the outer side is stretched or partly torn, the area swells and bruises, and putting weight on the foot hurts.

NICE Clinical Knowledge Summaries describe a sprain as a stretch or tear of a ligament, graded by severity, and note that the ankle is one of the commonest places for it. Typical features are pain around the joint, tenderness, swelling, bruising, pain on standing and reduced function. After a severe injury the joint may feel as if it gives way.

A strain is different: it is an overstretched or torn muscle or tendon rather than a ligament. The NHS table of differences places strains most often in the feet, legs and back, and sprains most often in wrists, ankles, thumbs and knees. In practice the first-aid approach is the same, which is one reason the two are often lumped together.

The table sets out the usual candidates. It is a way of thinking about the pattern, not a self-diagnosis; the NHS is clear that anyone unsure whether an ankle is broken should have it looked at.

The NHS page on a broken ankle separates two levels of urgency. The first is NHS 111: the injury is very painful or the pain is getting worse, there is a large amount of swelling or bruising that is increasing, it hurts to put weight on it, it feels very stiff or hard to move, or there is a very high temperature or shivering that could mean infection.

The second level is A&E or 999. The NHS lists an ankle at an odd angle, a bone sticking out, a bad cut or wound, severe pain, or toes that look blue or white or feel numb. The NHS sprains page adds that hearing a crack when the injury happened, numbness, tingling or pins and needles, and skin that has changed colour or is cold to touch suggest a broken bone. The NHS says not to drive yourself to A&E; ask someone else to drive or call 999.

• Hearing a crack at the moment of injury.

• The foot or ankle looking a different shape, or pointing at an odd angle.

• Numbness, tingling or pins and needles in the foot or toes.

• Toes or skin looking blue, grey or white, or feeling cold.

• A wound over the ankle, or a bone visible through the skin.

• Being unable to put weight on the ankle or take more than a few steps.

NICE guidance for clinicians lists the questions: how and when the injury happened, how severe and long-lasting the symptoms are, how active you normally are, and whether you have sprained the joint before or noticed it giving way. The mechanism matters, because a twist at walking pace and a fall from height carry different risks.

The examination looks at the shape and symmetry of the limb, whether the joint is stable, whether you can bear weight and how you walk, and the circulation and sensation in the foot. A deformity or misalignment raises the suspicion of a fracture or dislocation. NICE says an emergency department referral is appropriate when a fracture, dislocation, nerve or blood supply problem or an open wound is suspected, and that symptoms out of proportion to the injury deserve a specialist opinion.

The NHS says a broken ankle is usually confirmed or excluded with an X-ray, which also shows how bad any break is. X-rays can sometimes be arranged at an urgent treatment centre, and some people are referred on to hospital. CKS advises that an X-ray is considered when there is concern about the extent of the injury, associated injuries or a suspected fracture; not every sprain needs one.

If it is a break, the NHS describes a range of treatments depending on severity: none for a very minor break, a supportive boot, a plaster cast, realignment by a doctor after a numbing injection, or surgery to fix the bones. Follow-up appointments check healing.

For the first two to three days the NHS recommends PRICE: protection, rest, ice, compression and elevation. Ice means an ice pack, or frozen vegetables wrapped in a tea towel, held on the injury for up to 20 minutes every 2 to 3 hours. A bandage supports the ankle during the day, and keeping it raised on a pillow helps swelling.

The NHS also suggests avoiding heat, alcohol and massage for the first couple of days because they can increase swelling. For pain it names paracetamol, and ibuprofen gel, mousse or spray for swelling, with ibuprofen tablets if needed; a pharmacist can advise on what suits you, since anti-inflammatory tablets are not right for everyone.

If you suspect a fracture while waiting for care, the NHS broken ankle page adds practical steps: keep the ankle raised, do not eat or drink in case surgery is needed, remove jewellery from the ankle and toes, and avoid putting weight on it.

A broken ankle usually takes 6 to 8 weeks to heal but can take longer, according to the NHS, and a doctor will say how long a boot or cast is needed and how much weight can go through the leg. After either type of injury, moving the joint again prevents stiffness. The NHS says physiotherapy may help when a sprain is slow to settle, though NHS availability varies and waits can be long; in many areas people can refer themselves to a community musculoskeletal service.

CKS lists complications that are more likely after severe sprains: lasting instability, loss of function, chronic pain and swelling, repeat injury, and in some cases arthritis after the injury. That is why recovery that is slower than expected, or an ankle that keeps giving way, deserves review rather than being put up with.

A mild sprain that is improving can be managed at home with advice from a pharmacist. The NHS suggests seeing a GP if a suspected sprain is getting worse or is not improving after self-care. The urgent options are NHS 111 or an urgent treatment centre for significant pain, swelling or inability to walk, and A&E or 999 for the emergency signs above.

Anyone who has recurrent sprains, a sense of instability, or lasting swelling can ask about physiotherapy or an orthopaedic opinion. A private physiotherapist registered with the Chartered Society of Physiotherapy is an option the NHS itself mentions for people who prefer not to wait.