Pain in the back of the heel most commonly comes from a problem with the Achilles tendon or the structures immediately surrounding it. The specific cause depends on whether the pain developed gradually or suddenly, your age, and exactly where the tenderness is located. Several conditions share this location, but they feel different and have different triggers.
Achilles Tendinopathy: The Most Common Cause
The Achilles tendon connects your calf muscles to your heel bone, and irritation or degeneration of this tendon is the single most frequent reason for posterior heel pain. There are two types, and the distinction matters because they behave differently.
Insertional Achilles tendinopathy affects the lowest portion of the tendon, right where it attaches to the heel bone. Tenderness is concentrated within the bottom 2 centimeters of the tendon. You’ll typically notice stiffness after sitting or sleeping that eases once you start moving, then pain that worsens with physical activity. Many people with this condition find that the back of their shoe pressing against the heel becomes uncomfortable or even intolerable.
Mid-portion tendinopathy hits higher up, usually 2 to 6 centimeters above the heel bone. It’s more common in runners and tends to produce a noticeable thickening or lump in the tendon itself. The same pattern of morning stiffness and activity-related pain applies, but the sore spot is clearly above the heel rather than at it.
Both types develop gradually. They’re overuse injuries rather than sudden events, and they tend to get worse over weeks or months if the aggravating activity continues unchanged.
Haglund’s Deformity and Retrocalcaneal Bursitis
A Haglund’s deformity is a bony bump on the back of the heel bone itself, at the upper corner where the Achilles tendon sits. Not everyone with this bump has pain. Problems start when the bump irritates the retrocalcaneal bursa, a small fluid-filled sac that sits between the tendon and the bone to reduce friction. When that bursa becomes inflamed, you get retrocalcaneal bursitis, and the two conditions often exist together.
The hallmark is swelling and redness at the back of the heel, right where the upper edge of a shoe’s heel counter sits. Pressing on either side of the tendon at that spot (rather than directly on the tendon) reproduces the pain. This is different from Achilles tendinopathy, where the tenderness is on the tendon itself. The distinction can be subtle, and imaging sometimes helps sort it out, but the location and character of the swelling are the main clues.
Sever’s Disease in Children and Teens
If your child is between 8 and 15 years old and complaining about heel pain, Sever’s disease is the most likely explanation. It’s the single most common musculoskeletal complaint in active kids in that age range. The condition involves irritation of the growth plate at the back of the heel bone, which hasn’t yet fused into solid bone.
Running, jumping, and walking all increase the load on this growth plate, and sports with repetitive impact are the biggest triggers. Running is the activity most closely associated with Sever’s disease. The classic diagnostic test involves squeezing both sides of the heel simultaneously. If that squeeze reproduces the pain, it strongly points toward this diagnosis. Sever’s disease resolves on its own once the growth plate closes, but activity modification and supportive footwear help manage symptoms in the meantime.
Achilles Tendon Rupture
A rupture is the one cause of back-of-heel pain that demands immediate attention. Unlike tendinopathy, which builds slowly, a rupture happens in an instant. Most people hear or feel a distinct pop, followed by sharp pain in the back of the ankle and lower leg. The sensation is often described as feeling like someone kicked you in the calf.
The defining sign is functional: you can’t push off with the injured foot when walking, and you can’t rise up onto your toes on that leg. Swelling near the heel develops quickly. If you heard a pop and can’t walk normally afterward, this needs same-day medical evaluation. Ruptures most often happen during explosive movements like sprinting, jumping, or sudden direction changes, particularly in recreational athletes who aren’t consistently active.
What Increases Your Risk
Several factors make posterior heel pain more likely. Tight calf muscles put extra tension on the Achilles tendon and its insertion point with every step. Training errors, particularly sudden jumps in running mileage or intensity, are a well-recognized trigger for tendon problems. Weekend warriors who go from sedentary weekdays to intense weekend activity are especially vulnerable to both tendinopathy and rupture.
The role of footwear is widely discussed but less clear-cut than you might expect. Supportive shoes and avoiding completely flat soles are commonly recommended, but the actual evidence linking specific shoe types to posterior heel pain is limited. What does seem to matter is that shoes with a rigid or prominent heel counter can directly aggravate a Haglund’s bump or an already-irritated tendon insertion. If the back of your shoe presses into the sore spot, that mechanical pressure alone can keep the problem going.
Weak toe flexor muscles and altered walking patterns also play a role. People with heel pain tend to shift how they use their ankle during movement, relying less on the calf muscles to push off. This compensation can become self-reinforcing, as the tendon gets loaded differently and has less opportunity to recover normally.
How These Conditions Are Managed
Most causes of posterior heel pain respond to conservative treatment, but patience is essential. Tendon problems in particular heal slowly because tendons have limited blood supply compared to muscles.
For Achilles tendinopathy, the cornerstone of treatment is a structured loading program. Calf stretching, holding each stretch for 30 seconds and repeating two to three times per leg a few times daily, helps lengthen the tendon and calf complex. Progressive strengthening exercises gradually increase the tendon’s capacity to handle load. The goal isn’t rest. It’s finding the right amount of activity that challenges the tendon without flaring symptoms, then building from there.
For retrocalcaneal bursitis and Haglund’s-related pain, reducing direct pressure on the bump is the first priority. Open-backed shoes, padding, or shoes with a softer heel counter can make a significant difference. Ice and anti-inflammatory measures help calm acute flare-ups, but if the bony prominence is large enough, it may continue to cause problems despite these measures.
Recovery timelines vary widely. Mild cases may improve within a few weeks of modifying activity and footwear. More stubborn cases can take several months. If symptoms persist beyond five or six months of consistent conservative care, additional interventions like guided injections or, in rare cases, surgery become part of the conversation.
How to Tell Which Condition You Have
You can narrow it down based on a few key details. Pain directly on the tendon, especially with morning stiffness that loosens up, points toward Achilles tendinopathy. A visible bump with swelling on either side of the tendon suggests a Haglund’s deformity with bursitis. A sudden pop with immediate inability to push off is a rupture until proven otherwise. And heel pain in an active child between 8 and 15 that hurts when you squeeze both sides of the heel is almost certainly Sever’s disease.
The location matters more than anything else. Pain right at the bone where the tendon attaches is insertional tendinopathy. Pain a few centimeters higher is mid-portion tendinopathy. Pain to the sides of the tendon near the bone is bursitis. These conditions can also overlap, with more than one contributing to your symptoms at the same time.