Heel pain most often comes from plantar fasciitis, a condition where the thick band of tissue running along the bottom of your foot becomes irritated and inflamed. But several other structures in and around the heel can generate pain, and where exactly you feel it tells you a lot about what’s going on. The bottom of the heel, the back of the heel, and the sides of the heel each point to different problems with different causes and different recovery timelines.
Plantar Fasciitis: The Most Common Cause
The plantar fascia is a tough band of tissue connecting your heel bone to the base of your toes. It supports your arch and absorbs shock every time you take a step. When repeated stress causes small tears in this tissue, the area becomes inflamed and painful. The hallmark symptom is a stabbing pain in the bottom of your foot near the heel, and it’s typically worst during your first few steps after waking up.
That morning pain has a straightforward explanation. While you sleep, your foot relaxes into a pointed position, allowing the fascia to contract and tighten. When you stand and put weight on it, the tissue stretches abruptly across those micro-tears. The same thing happens after any long period of sitting or standing still. Once you walk around for a few minutes, the tissue loosens and the sharp pain often fades to a dull ache.
Most people recover within several months using conservative approaches: icing the area, consistent stretching of the calf and foot, and avoiding or modifying the activities that trigger pain. Supportive shoes and over-the-counter arch inserts can reduce the strain on the fascia during that healing window.
How Foot Mechanics Make It Worse
The way your foot moves when you walk plays a major role in heel pain. Your foot is designed to roll slightly inward after your heel strikes the ground, a motion called pronation that cushions impact. When your foot rolls inward too much (overpronation), that natural shock absorption breaks down. The arch flattens excessively, impact forces increase, and the plantar fascia gets stretched beyond what it can handle.
Over time, this abnormal loading causes microdamage in the soft tissues. It’s not just the heel that suffers. The increased forces travel up through the ankle, knee, and hip as those joints compensate for the misalignment. This is why people with flat feet or worn-out shoes tend to develop heel pain more frequently, and why correcting foot mechanics with supportive footwear or custom orthotics often makes a meaningful difference.
Achilles Tendonitis: Pain at the Back of the Heel
If your pain is at the back of the heel rather than the bottom, the Achilles tendon is the likely culprit. This tendon connects your calf muscles to your heel bone, and it comes in two varieties of trouble.
Noninsertional tendonitis affects the middle portion of the tendon, above where it attaches to the heel. The tendon fibers break down over time, developing tiny tears that cause swelling and thickening. This type is more common in younger, active people, particularly runners.
Insertional tendonitis affects the lower portion of the tendon right where it anchors to the heel bone. Bone spurs frequently develop at this attachment point. Tight calf muscles are a common driver because they place extra stress on the insertion site. Unlike the noninsertional type, insertional tendonitis can develop at any activity level and any age, though runners remain the most affected group.
You can often tell the two apart by pressing on the area. Pain in the middle of the tendon points to noninsertional tendonitis. Pain or a bony bump right at the back of the heel, where the tendon meets bone, suggests the insertional type.
Heel Bursitis
Tucked between your heel bone and Achilles tendon is a small fluid-filled sac called a bursa, which reduces friction between the two structures. When this bursa becomes inflamed (retrocalcaneal bursitis), it produces pain and swelling at the back of the heel that can feel very similar to Achilles tendonitis. The key difference is that bursitis tends to cause more diffuse swelling around the heel rather than tenderness along the tendon itself. Tight shoes that press against the back of the heel, repetitive impact, and sudden increases in activity are common triggers.
Stress Fractures in the Heel Bone
A calcaneal stress fracture is a small crack in the heel bone that develops gradually from repetitive impact. Unlike an acute fracture from a fall or collision, stress fractures build over days to weeks. The pain tends to be generalized across the heel rather than pinpointed to one spot, and it gets worse with weight-bearing activity.
One clinical clue is the squeeze test: if pressing on both sides of the heel (rather than the bottom) reproduces the pain, a stress fracture is more likely than plantar fasciitis. Standard X-rays can miss early stress fractures, so an MRI or bone scan is typically needed to confirm the diagnosis. Runners, military recruits, and anyone who rapidly increases their training load are at highest risk.
Nerve Compression: Burning and Tingling
Tarsal tunnel syndrome occurs when a nerve on the inner side of the ankle gets compressed as it passes through a narrow space near the ankle bone. The symptoms are distinctly different from the mechanical pain of plantar fasciitis. Instead of a sharp or aching pain, you’ll notice burning, tingling, or numbness along the bottom of the foot and toes. The sensation can radiate outward from the inner ankle, and it often worsens after long periods of standing or walking. This condition is sometimes misdiagnosed as plantar fasciitis because the symptoms overlap in location, but the neurological quality of the pain (burning, electric, numb) is the distinguishing feature.
Heel Spurs: Often Not the Real Problem
Heel spurs are bony growths that develop on the underside of the heel bone. They show up frequently on X-rays, which leads many people to assume the spur itself is causing their pain. The reality is more nuanced. About 15% of people with no heel pain at all have visible heel spurs on imaging. Less than 5% of people with spurs actually experience pain from them. Spurs appear in roughly half of patients with plantar fasciitis, but the fascia inflammation, not the spur, is almost always the pain generator. Treating the plantar fasciitis resolves the pain even though the spur remains on the bone.
Heel Pain in Children and Teens
In kids between ages 8 and 14, the most common cause of heel pain is Sever’s disease (calcaneal apophysitis). It’s not actually a disease. It’s irritation of the growth plate at the back of the heel bone during periods of rapid growth. The heel bone doesn’t fully harden until around age 15, and during growth spurts, the Achilles tendon can pull on that still-developing bone. Active children involved in running and jumping sports are especially prone to it. The condition is diagnosed through a physical exam where gentle pressure on the heel reproduces the pain, and it resolves on its own once growth in that area is complete.
When Heel Pain Signals Something Systemic
Occasionally, heel pain isn’t a local injury at all but a sign of a systemic inflammatory condition. Ankylosing spondylitis and other forms of inflammatory arthritis can cause a specific type of inflammation called enthesitis, which targets the points where tendons and ligaments attach to bone. The back of the heel (at the Achilles tendon attachment) and the underside of the heel (at the plantar fascia attachment) are two of the most common sites for enthesitis in the body.
What sets this apart from a typical overuse injury is the pattern. Inflammatory heel pain tends to be worse after rest (especially in the morning), improves with movement, and may be accompanied by stiffness or pain in the lower back, other joints, or where the ribs meet the breastbone. If your heel pain doesn’t respond to standard treatments, comes and goes without a clear mechanical trigger, or appears alongside joint stiffness elsewhere, an inflammatory condition may be worth investigating.