Pain at the back of the heel most commonly comes from irritation of the Achilles tendon where it attaches to the heel bone, inflammation of the fluid-filled cushion (bursa) behind the heel, or a bony enlargement on the heel itself. Less often, it signals a stress fracture or an inflammatory condition like gout. The cause usually depends on exactly where the pain sits, how it started, and what makes it worse.
Insertional Achilles Tendinitis
The Achilles tendon connects your calf muscles to your heel bone, and the spot where it anchors into the bone is one of the most common sources of back-of-heel pain. This is called insertional Achilles tendinitis. Unlike mid-tendon problems that cause pain a few inches above the heel, insertional tendinitis hurts right at the bottom of the heel’s back surface, often where you can feel the tendon meet the bone.
The pain typically builds gradually over weeks or months. It tends to be worst when you first start moving after rest, like getting out of bed or standing up from a desk, and again after prolonged activity. Stiff-soled shoes and hill walking often aggravate it. You might notice a thickened or slightly swollen area at the back of the heel, and the spot is usually tender to the touch.
This condition develops when the tendon fibers at the attachment point break down faster than the body can repair them. It’s common in runners and people who suddenly increase their activity level, but it also affects people who aren’t particularly active, especially as tendons lose elasticity with age.
Haglund’s Deformity and Bursitis
A bony bump on the upper back corner of the heel bone, known as Haglund’s deformity, is another frequent cause. This enlargement sits right where the Achilles tendon attaches, and it can irritate both the tendon and the small bursa (a fluid-filled sac that reduces friction) tucked between the tendon and the bone. When that bursa becomes inflamed, the condition is called retrocalcaneal bursitis.
The telltale sign is swelling, warmth, and redness at the back of the heel. During a careful exam, it’s possible to distinguish whether the inflammation sits in front of the Achilles tendon (the bursa) or behind it (the tendon itself), though both can be present at the same time. Haglund’s deformity is sometimes called “pump bump” because rigid shoe backs press directly against the bony prominence, making the irritation worse. A standard lateral X-ray is usually enough to confirm the bony enlargement.
Calcaneal Stress Fracture
A stress fracture in the heel bone causes a distinctly different pain pattern than soft tissue problems. The pain is deep and aching rather than sharp, and it’s localized directly over the bone rather than along the tendon. It gets worse with activity and with weight-bearing, and unlike Achilles tendinitis, it doesn’t tend to ease up once you’ve been walking for a few minutes.
Swelling of the heel area is common, and sometimes bruising appears along the sole of the foot. Squeezing both sides of the heel simultaneously often reproduces the pain, which helps distinguish it from tendon issues. Stress fractures are more likely in runners who have recently increased mileage, people with low bone density, and military recruits or others doing repetitive impact activity. They don’t always show up on initial X-rays, so an MRI is sometimes needed.
Gout and Inflammatory Arthritis
When back-of-heel pain comes on suddenly and intensely, especially at night, an inflammatory condition like gout deserves consideration. Gout flares typically affect one joint at a time and cause the area to feel swollen, red, and warm. The pain can be severe enough to wake you from sleep.
Gout is caused by a buildup of urate crystals in and around joints. Certain foods, alcohol, some medications, and physical trauma can trigger a flare. Over time, repeated flares can lead to hard lumps of crystal deposits forming under the skin near joints. While gout most famously strikes the big toe, it can affect the heel and ankle as well. If your heel pain arrived abruptly without any change in activity or footwear, and the area looks inflamed, this is worth investigating with a blood test and possibly joint fluid analysis.
Sever’s Disease in Children
If your child is complaining about pain at the back of the heel, the most likely explanation is Sever’s disease (calcaneal apophysitis). This typically affects kids between ages 9 and 13, especially those active in impact sports like soccer, basketball, or gymnastics. The growth plate at the back of the heel bone is still developing during these years, and repetitive stress from running and jumping irritates it.
The pain is usually at the very back or bottom edge of the heel and worsens during and after sports. It resolves on its own once the growth plate fully matures, though reducing activity and using supportive footwear can help manage symptoms in the meantime. If a child outside the 9 to 13 age range has persistent heel pain, other causes should be explored.
When the Tendon Tears
A complete or partial Achilles tendon tear is the most serious cause of sudden back-of-heel pain. Many people report hearing or feeling a pop at the moment it happens, followed by immediate difficulty walking. The calf may swell and bruise, and you might feel a gap or soft spot in the tendon a few centimeters above the heel bone. Complete tears typically occur 2 to 6 centimeters above where the tendon inserts into the heel.
A simple clinical test, where a provider squeezes the calf muscle to see if the foot flexes, is 96% sensitive and 93% specific for detecting a tear. If you experienced a sudden onset of pain during physical activity and now can’t push off your foot normally, this needs prompt evaluation.
How Footwear Affects the Back of the Heel
The “heel drop” of your shoes, meaning the height difference between the heel and the forefoot, directly influences how much stress reaches the back of your heel. A lower-drop shoe shifts more impact force to the calves, Achilles tendon, and lower leg. A higher-drop shoe offloads some of that stress to the knees and hips instead.
If you’re dealing with Achilles-related heel pain, a shoe with a slightly higher heel drop can reduce the pull on the tendon. Conversely, switching abruptly to minimalist or low-drop shoes without a gradual transition is a common trigger for posterior heel pain, because it dramatically increases the demand on the Achilles tendon. Rigid heel counters (the stiff back of the shoe) can also press against a Haglund’s bump and worsen bursitis, so softer or open-backed shoes often help in those cases.
Recovery and Rehabilitation
For Achilles tendinitis, eccentric exercises are the most effective rehabilitation approach. These involve slowly lowering your heel off the edge of a step, using the healthy leg to rise back up. The most widely used protocol calls for 180 eccentric repetitions per day (typically broken into sets of 15, repeated across the day), continued for at least 12 weeks. That volume sounds like a lot, but it takes only about 15 to 20 minutes total.
Research shows that doing repetitions “as tolerated” rather than hitting the full 180 count produces similar results for pain relief by six weeks, so the exact number matters less than consistency. Some protocols extend to six months if symptoms persist. The key principles are gradually increasing the load, working through a full range of motion, and slowly building the speed of the movement as the tendon adapts.
For bursitis and Haglund’s deformity, initial treatment focuses on reducing pressure on the area through shoe modifications, heel lifts, and icing. Stress fractures require a period of reduced or non-weight-bearing activity, typically several weeks, to allow the bone to heal before gradually returning to impact activity.