Pain at the back of your foot usually comes from the Achilles tendon or the tissue surrounding it where it connects to your heel bone. This area handles enormous force every time you walk, run, or push off the ground, making it one of the most common sites for overuse injuries. The specific cause depends on exactly where the pain sits, how it started, and how long you’ve had it.
Achilles Tendinopathy: The Most Common Cause
The Achilles tendon is a thick band of tissue running from your calf muscles down to your heel bone. It’s the largest tendon in your body, and when it’s overworked, it’s the most likely source of pain at the back of your foot. This pain shows up in two distinct spots.
Non-insertional tendinopathy causes pain a few centimeters above the heel bone, in the middle portion of the tendon. This is the more common form. You might notice the tendon feels thickened or tender when you pinch it between your fingers. It tends to flare up with increased activity, particularly running or jumping.
Insertional tendinopathy causes pain right where the tendon attaches to the heel bone. This type is more stubborn and often linked to years of cumulative stress. It can hurt even when you’re not exercising, especially when pressing on the back of the heel or wearing shoes with rigid heel counters.
There’s an important distinction between acute inflammation (tendonitis) and the more chronic, degenerative form (tendinosis). True tendonitis involves active inflammation, usually triggered by explosive activities like sprinting or jumping. Tendinosis, on the other hand, develops gradually as the tendon tissue breaks down and becomes disorganized over time. Most people with lingering Achilles pain actually have tendinosis rather than tendonitis, which matters because the treatment approach differs.
Retrocalcaneal Bursitis
A small fluid-filled sac called the retrocalcaneal bursa sits between your heel bone and your Achilles tendon, acting as a cushion. When this sac becomes inflamed, it produces pain at the very back of the heel that can easily be mistaken for a tendon problem. The telltale signs include redness, warmth, and visible swelling on the back of the heel, along with stiffness that limits how much you can move your ankle.
Bursitis can develop from overuse, but it also has some less obvious triggers. A direct impact injury to the heel can set it off, and inflammatory conditions like gout or rheumatoid arthritis are known causes. If you also develop a fever alongside heel swelling, that could indicate an infected bursa, which needs prompt medical attention.
Haglund’s Deformity (Pump Bump)
If you can see and feel a hard bump on the back of your heel, you may have a Haglund’s deformity. This is a bony growth on the heel bone right where the Achilles tendon attaches. The bump presses against the back of your shoes, creating friction, pain, swelling, and sometimes skin discoloration around the area.
It’s nicknamed “pump bump” because rigid-backed shoes like high heels make it especially painful. But any footwear with a stiff heel counter can aggravate it. Diagnosis is straightforward: a provider can feel the bump during a physical exam, and X-rays confirm the bony growth and rule out other problems.
Sever’s Disease in Kids and Teens
If your child is complaining about pain at the back of the heel, Sever’s disease is the most likely explanation. It’s extremely common between ages 8 and 14, when growth spurts put extra stress on the growth plate in the heel bone. The Achilles tendon pulls on this growth plate during activity, causing irritation.
Most kids report pain in both heels rather than just one. You might notice them walking on their toes or limping after running. The heel is painful when squeezed from the sides, and stiffness is often worst first thing in the morning. Despite the name, it’s not a disease. It resolves on its own once the growth plate fully hardens, though activity modification and supportive shoes help manage pain in the meantime.
When Pain Signals Something Serious
A sudden pop or snap at the back of your ankle, especially during intense physical activity, may indicate an Achilles tendon rupture. This is typically followed by sharp, severe pain and difficulty walking. Most people with a ruptured Achilles can still walk and move their ankle to some degree, which leads many to assume the injury isn’t serious. It is. A provider can often feel a gap in the tendon at the tear site during a physical exam.
If you heard or felt a pop before your symptoms started, get evaluated right away, even if you can bear weight on it.
How Footwear Affects the Back of Your Foot
The “heel drop” of your shoe, meaning the height difference between the heel and the forefoot, directly affects how much tension your Achilles tendon has to absorb. A higher heel drop shortens the tendon’s working length and reduces strain on it. This is why shoes with a modest heel lift often provide relief for Achilles pain.
Low-drop or minimalist shoes do the opposite. They force the Achilles tendon to stretch further with each step, which can be beneficial for building tendon resilience over time but problematic if you switch to them too quickly or already have an irritated tendon. If the back of your foot hurts and you recently changed your shoes, that transition may be the trigger.
What Recovery Looks Like
Achilles tendinopathy is notoriously slow to heal. If you’ve had symptoms for a few months already, expect a few more months of recovery with conservative treatment. That timeline frustrates a lot of people, but the tendon simply doesn’t have the blood supply that muscle does, so tissue repair takes longer.
The most evidence-supported exercise approach for Achilles problems is eccentric loading, which means slowly lowering your body weight through the tendon rather than pushing up. A basic version involves standing on your toes with both feet on a step, then lifting one foot and lowering yourself slowly on the affected leg. Programs typically start with 3 sets of 10 repetitions and progress to 3 sets of 15, with increasing speed and resistance as pain allows. These exercises should begin after the initial acute pain has settled, usually 7 to 10 days after symptoms start improving.
If six months of conservative treatment hasn’t made a meaningful difference, surgery may become part of the conversation. But most cases of posterior foot pain respond to a combination of activity modification, appropriate footwear, and a gradual loading program. The key is patience and consistency rather than rest alone.
Pinpointing the Cause by Pain Location
Where exactly you feel pain narrows the list of likely causes considerably:
- A few inches above the heel bone: Non-insertional Achilles tendinopathy, the most common culprit in active adults.
- Right at the heel bone: Insertional tendinopathy, Haglund’s deformity, or retrocalcaneal bursitis. Visible swelling or a hard bump helps distinguish between them.
- Both heels in a child or teen: Sever’s disease, particularly if they’re in a growth spurt and active in sports.
- Sudden onset with a pop: Possible Achilles tendon rupture requiring immediate evaluation.
If your pain is mild and linked to a recent increase in activity, scaling back and trying a shoe with a higher heel drop is a reasonable first step. Pain that persists beyond a few weeks, wakes you up at night, or comes with visible swelling or redness warrants a closer look. Ultrasound and MRI are both highly accurate for evaluating Achilles tendon problems, with both methods detecting tendon thickening and damage with sensitivity above 80%.