Pain in the back of the heel most commonly comes from problems with the Achilles tendon, the bursa (a small fluid-filled cushion), or the heel bone itself. These three structures sit close together, and irritation in one often spreads to the others. Orthopedic specialists actually refer to the combination of insertional Achilles tendon inflammation, bursitis, and a bony enlargement of the heel as the “terrible triad” of posterior heel pain because they so frequently occur together.
Achilles Tendon Damage
The Achilles tendon connects your calf muscles to the back of your heel bone. Repetitive stress from walking, running, or jumping loads this tendon over and over, and that cumulative strain can cause damage right where the tendon attaches to bone. This is called insertional Achilles tendinopathy, and it’s the single most common reason for pain at the back of the heel.
The nature of the damage matters. In the early stages, small tears in the tendon trigger inflammation, producing pain and swelling. But if overuse continues without adequate rest, the problem shifts from active inflammation to structural degeneration. The tendon’s collagen fibers lose their organized, parallel alignment and are replaced by weaker, immature fibers that can’t bear load as well. The tendon surface changes from white and firm to dull, brownish, and soft. Counterintuitively, at this chronic stage inflammatory cells are rarely present, which is why anti-inflammatory medications alone often don’t resolve long-standing tendon pain.
Over time, the damaged portion of the tendon can calcify, forming hard, bone-like deposits where the tendon meets the heel. These calcifications are visible on X-rays and can make the back of the heel feel lumpy or enlarged.
Retrocalcaneal Bursitis
A small, fluid-filled sac called the retrocalcaneal bursa sits between the Achilles tendon and the heel bone. Its job is to reduce friction so the tendon can glide smoothly. When this bursa becomes inflamed, it swells and produces pain, redness, and warmth at the back of the heel. You might notice a soft, tender bump that’s distinct from the firmer feel of bone or tendon.
Bursitis here is usually caused by overuse and repetitive ankle motion, which is why it’s especially common in runners, dancers, and other athletes. It can also be triggered by a direct impact injury or by inflammatory conditions like gout or rheumatoid arthritis. When the heel bone is abnormally shaped or enlarged, the bursa gets pinched between bone and tendon with every step, making inflammation almost inevitable.
Haglund’s Deformity (Pump Bump)
Haglund’s deformity is a bony enlargement on the upper back corner of the heel bone. It develops gradually over years and creates a visible bump that can press against shoes, irritating the overlying skin, the bursa, and the Achilles tendon. The nickname “pump bump” comes from its association with rigid-backed shoes like pumps, which press directly against the prominence.
The bony enlargement itself isn’t always painful. The problem starts when it rubs against footwear or compresses the soft tissues around it. This mechanical irritation commonly leads to retrocalcaneal bursitis and thickening of the Achilles tendon, which is why Haglund’s deformity rarely exists in isolation. If you can see or feel a hard, bony bump at the back of your heel and your pain gets worse in stiff shoes, this is a likely contributor.
Growth Plate Irritation in Children
In children and young teenagers, the most common cause of posterior heel pain isn’t the tendon or bursa but the growth plate in the heel bone. This condition, called Sever’s disease (or calcaneal apophysitis), typically appears between ages 8 and 15, with average onset around age 12 in boys and 11 in girls.
During growth spurts, bones lengthen faster than muscles and tendons can stretch to keep up. This creates extra tension where the Achilles tendon attaches to the still-developing growth plate at the back of the heel. In a child’s skeleton, the growth plate is the weakest link in the chain, unlike in adults where the tendon itself gives way first. Repetitive pulling from running and jumping sports causes microtrauma and chronic irritation at this vulnerable spot. The condition is self-limiting and resolves once the growth plate fully hardens, but it can sideline active kids for weeks or months.
Inflammatory and Systemic Causes
Sometimes posterior heel pain isn’t caused by overuse at all but by an autoimmune or inflammatory condition attacking the spot where tendons and ligaments anchor to bone. This type of inflammation, called enthesitis, is a hallmark of certain forms of arthritis. Recurring enthesitis at the heel is one of the clues doctors use to diagnose psoriatic arthritis and ankylosing spondylitis.
If your heel pain came on without an obvious increase in activity, affects both heels, or is accompanied by stiffness in your lower back, swollen fingers or toes, or skin changes like psoriasis patches, a systemic inflammatory condition may be the underlying cause. This pattern is distinct from the typical overuse scenario and calls for a different treatment approach focused on controlling the immune response rather than modifying activity.
How to Tell These Conditions Apart
The location and timing of your pain offer useful clues. Insertional Achilles tendinopathy tends to hurt right at the back of the heel where you can feel the tendon meeting the bone, and it worsens with activity, especially pushing off while walking or running. Retrocalcaneal bursitis produces a softer, more diffuse tenderness slightly deeper between the tendon and bone, often with visible swelling on either side of the tendon. A Haglund’s deformity is identifiable as a hard, bony bump that gets more irritated in rigid shoes.
It’s worth distinguishing posterior heel pain from plantar fasciitis, which affects the bottom of the heel rather than the back. Plantar fasciitis classically causes stabbing pain with your first steps in the morning that eases as you move around, then returns after long periods of standing or sitting. Pain at the back of the heel from Achilles problems, by contrast, often involves stiffness in the morning but tends to flare most during and after physical activity.
What Helps Posterior Heel Pain
For most overuse-related causes, the first step is reducing the load on the affected area. A simple heel raise inserted into your shoe lifts the heel bone slightly, which reduces the pull of the calf muscles and Achilles tendon on the back of the heel. Switching to shoes with a softer, less rigid heel counter can make a significant difference, particularly if a Haglund’s deformity is involved.
For Achilles tendinopathy specifically, targeted exercises that strengthen the tendon under controlled conditions are the best-supported treatment. These typically involve slowly lowering your heel off the edge of a step (eccentric loading). One widely used protocol calls for three sets of 15 repetitions, performed twice daily for 12 weeks. That may sound like a lot, but the research consistently shows that gradual, progressive loading helps the tendon remodel and regain strength. The exact sets and reps matter less than the principle: consistently challenge the tendon at a level that’s uncomfortable but manageable, and increase the load over time.
Ice and temporary activity modification help manage acute flare-ups of bursitis or tendon inflammation. For bursitis driven by inflammatory arthritis, treatment focuses on the underlying condition. Haglund’s deformity that doesn’t respond to shoe changes or padding may eventually require surgical removal of the bony prominence.
Signs of an Achilles Tendon Rupture
A sudden pop or snap at the back of your ankle during intense activity, followed by sharp pain and difficulty walking, suggests a possible Achilles tendon rupture rather than a gradual overuse injury. Some people describe it as feeling like they were kicked in the heel. A full rupture requires prompt medical evaluation even if you can still put some weight on the foot, because the tendon won’t heal properly on its own without treatment.