What usually causes itEmerging evidence
No study we found has counted how often each cause produces pain at the back of the heel, so this list comes from guidelines and professional bodies. The commonest is insertional Achilles tendinopathy: pain where the tendon joins the heel bone, within about 2 centimetres of it, as the Dutch Achilles guideline defines it. It can happen at any activity level, though it's commoner in runners, and it often follows calf tightness, a change of shoes or a jump in activity; bone spurs often form at the back of the heel. Achilles tendinopathy is commonest between 30 and 60, and an NHS trust lists diabetes, high cholesterol, inflammatory arthritis, long-term steroids and some antibiotics among the things that raise the risk.
An enlarged bony bump on the back of the heel (Haglund's deformity) can rub on the tendon, and the fluid sac between the tendon and the bone can become inflamed (bursitis); Arthritis UK says tight shoes and high heels regularly cause it. A few centimetres higher up the cord, 2 to 7 centimetres above the heel, is mid-portion tendinopathy. In children aged about 8 to 15, the growth plate at the back of the heel can become irritated with running and jumping (Sever's disease).
Sources 1, 2, 3, 4, 5, 6
Telling the tendon, the bump and the bursa apartEmerging evidence
They often come together. Tendon pain sits right where the tendon meets the bone and is worst on the first steps in the morning and after rest; it can be worse with running, hills or stairs and in shoes that press. A Haglund's bump is a hard, enlarged bump that shoes rub. Bursitis is a red, painful, swollen lump between the tendon and the bone. A tendon that is sore 2 to 7 centimetres higher up is the mid-portion type, which responds to slightly different exercises.
Where exactly it hurts matters for the plan: lowering the heel below the edge of a step suits mid-portion pain, but not pain where the tendon meets the bone, so this guide keeps heel exercises on the flat.
Sources 2, 4, 1, 7, 3
Bone, inflammation, antibiotics and other causesStrong evidence
A stress fracture of the heel bone causes heel pain during exercise and can be mistaken for plantar fasciitis or a heel spur. Inflammation where tendons attach to bone (enthesitis) behind the heel is a feature of ankylosing spondylitis, and Arthritis UK links psoriatic and reactive arthritis with Achilles pain; NICE asks for a rheumatologist's assessment when it's persistent, in several places, or comes with back pain, eye inflammation, psoriasis, bowel inflammation or a recent gut or urinary infection.
Fluoroquinolone antibiotics, such as ciprofloxacin, can damage the Achilles within 48 hours of starting and up to several months after stopping, the UK medicines regulator (MHRA) says, with a higher risk over 60, with kidney problems, after an organ transplant and with steroid medicines. Rarely, thickened, lumpy Achilles tendons are a sign of inherited high cholesterol (familial hypercholesterolaemia). A bursa can become infected, which makes the heel red, hot and swollen, sometimes with a high temperature.
Sources 8, 9, 10, 4, 1, 11, 12, 13, 14
Children: Sever's diseaseStrong evidence
Sever's disease is one of the commonest causes of heel pain in growing children: pain at the back or sides of the heel during and after running and jumping, sometimes in both heels, with a heel bone that's tender when pressed along the sides or underneath. US orthopaedic surgeons say it won't come back once the growth plate has finished growing. In trials of 101 and 124 children, the pain eased over a few months whether they waited, wore a heel raise, had new shoes or orthoses, or had physiotherapy.
A limp you can't explain, pain at night or at rest, swelling or redness needs a GP, and a limp with a high temperature and feeling unwell is a 999 or A&E matter, the NHS says.
Sources 5, 15, 16, 17
A note on night pain at the back of the heelEmerging evidence
Achilles pain is typically worst on the first steps in the morning, after rest and after activity. Pain that is constant, wakes you, or comes with a fever, weight loss, swollen joints or back pain that is worse at night points elsewhere: inflammatory arthritis, an infection, a problem in the bone or a stress fracture that aches at rest. This is our reading of the sources; no study we found measured night pain at the back of the heel.
Sources 6, 3, 7, 2, 9, 14, 18, 8
Tests and scansEmerging evidence
Achilles tendinopathy is diagnosed from your story and an examination, and scans usually aren't needed. If imaging is needed for pain where the tendon meets the bone, the Dutch guideline prefers ultrasound, with a side X-ray of the heel to look at the bone; US orthopaedic surgeons say X-rays show bone spurs and magnetic resonance imaging (MRI) helps plan surgery. What a scan shows doesn't predict how it will go.
A suspected rupture is checked with a calf squeeze test, which picked up 96% of ruptures in a study of 174 people, and sometimes ultrasound. Sever's disease looks the same as a normal growing heel on X-ray, so X-rays are only used to rule out other causes. Suspected spondyloarthritis needs a rheumatologist.
Sources 1, 3, 2, 19, 20, 5, 10
How it usually goesEmerging evidence
Most people with Achilles tendinopathy improve, but slowly. An NHS trust says most people notice some improvement within 8 to 12 weeks of exercise, another says recovery within 12 months is usual, and in the studies the Dutch guideline reviewed, 23% to 37% still had some symptoms up to 10 years later. NHS inform says talk to a healthcare professional if it hasn't improved within 12 weeks. Sever's disease settles once growth finishes and can flare with more sport until then. No one can promise a timescale.
Sources 3, 7, 1, 6, 5
