Haglund deformity

What it means

Haglund deformity is an enlarged, bony bump on the back of the heel bone (the calcaneus), right where the Achilles tendon attaches before it inserts lower down. The bump itself is simply an extra prominence of bone — a variation in shape rather than damage or disease — but its location matters, because it sits exactly where shoes and the Achilles tendon rub against it.

It's sometimes nicknamed "pump bump" because it's especially noticeable, and often irritated, by rigid-backed shoes such as pumps, dress shoes, or ice skates that press directly on that spot.

Why it appears on a CT or MRI report

Haglund deformity is usually visible on a plain X-ray as an enlarged, prominent back corner of the heel bone, but it's often picked up or further characterized on MRI when someone is being scanned for heel or Achilles pain. The report will describe the bony prominence itself and, importantly, whether there are signs of associated irritation nearby — such as inflammation of the small fluid-filled cushion (the retrocalcaneal bursa) that normally protects the tendon from the bone, thickening or degeneration of the Achilles tendon where it inserts, or fluid and swelling in the surrounding soft tissue.

What it usually means

Many people have some degree of Haglund deformity without ever having symptoms — it's a shape variation that can be entirely incidental, especially when found on a scan done for another reason. It becomes clinically relevant, and gets the label "Haglund syndrome," when the bump is large enough or the shoe pressure consistent enough that it causes ongoing irritation: pain and tenderness at the back of the heel, a visible red or thickened bump under the skin, and sometimes swelling that worsens with certain footwear or activity. This combination of bone prominence, bursal inflammation, and Achilles tendon irritation tends to develop gradually and is more common in people who wear stiff-backed shoes regularly or who are active in sports involving repetitive heel pressure.

When to follow up

If the report is otherwise incidental and you have no heel pain, no specific action is usually needed. If you do have pain, swelling, or a tender bump at the back of the heel, it's worth discussing with your doctor or a podiatrist — first-line treatment is usually simple, including changing to softer-backed or open-heeled shoes, heel pads, stretching, and anti-inflammatory measures, and most people improve without surgery. Persistent pain that doesn't respond to shoe changes and conservative care over several months, or pain that's affecting walking, is worth a more detailed evaluation, since a minority of cases benefit from a procedure to shave down the bony prominence.

A plain-language way to picture it

Picture the back of your heel like the corner of a shelf that sticks out a little further than the rest of the woodwork. Most of the time it just sits there, unnoticed. But if something keeps rubbing against that corner — a stiff shoe brushing past it thousands of times a day — the friction eventually irritates the skin and soft padding right at that spot. Sanding down that sharp corner, or simply routing traffic around it with softer shoes, is usually enough to stop the irritation.