Heel bursitis typically appears as a swollen, red or skin-toned bump at the back of the heel, often accompanied by warmth and tenderness. In early stages, you might only notice slight redness and puffiness. Over time, the swelling becomes more distinct and can develop into a soft, fluid-filled nodule between 1 and 3 centimeters across.
Early Visual Signs
In the beginning, heel bursitis doesn’t always look dramatic. The first visible changes are usually mild redness (or a slightly darker tone on deeper skin tones), some puffiness around the back of the heel, and skin that feels warm to the touch. At this stage, what you see may not match what you feel. The pain and tenderness can be more noticeable than the swelling itself, especially when pressing on the area or wearing shoes with rigid heel counters.
As inflammation continues over weeks or months, the area becomes more obviously swollen. The skin over the bursa may look stretched or shiny due to fluid buildup underneath. In some cases, superficial skin erosion develops from ongoing friction, leaving the skin rough, irritated, or slightly broken down where it rubs against your shoe.
What the Bump Looks Like Over Time
If heel bursitis goes untreated or becomes chronic, a soft, squishy nodule forms at the back of the heel. This bump is typically 1 to 3 centimeters in diameter and feels fluid-filled when you press on it (doctors call this “fluctuant,” meaning it gives slightly under pressure like a small water balloon). It can be red or simply match your natural skin color. The bump sits right where the Achilles tendon meets the heel bone, and it’s usually tender to touch.
This is different from a hard, bony bump. If you feel something firm and immovable in the same area, that’s more likely a Haglund’s deformity, a bony enlargement of the heel bone itself. The two conditions frequently coexist, though, because that bony prominence irritates the bursa and triggers inflammation. When both are present, you may see a hard bump underneath with soft, swollen tissue around it.
Haglund’s Deformity and the “Pump Bump”
Haglund’s deformity, sometimes called a “pump bump,” is a bony enlargement at the back of the heel where the Achilles tendon attaches. It creates a visible hard lump on the posterior heel that becomes especially noticeable from the side. When rigid shoe backs press against this prominence, the surrounding soft tissues get irritated, leading to bursitis, tendon thickening, and further swelling. This combination of bony bump plus inflamed bursa plus tendon irritation is known as Haglund’s syndrome.
The visual difference matters: a Haglund’s bump is hard, bony, and doesn’t change size day to day. The bursitis swelling layered on top of it is softer, may fluctuate with activity, and tends to be more red and warm. Many people with heel bursitis have both components, which can make the back of the heel look noticeably enlarged compared to the other foot.
Signs of Infection to Watch For
Most heel bursitis is caused by friction or overuse, not infection. But septic bursitis (an infected bursa) can look similar, which makes it tricky. Both cause swelling, redness, warmth, and tenderness. The key visual differences with an infected bursa are more intense, spreading redness that extends beyond the bump itself, visible wounds or skin breaks near the area, and signs of cellulitis (skin that looks tight, hot, and streaky red). Fever may accompany an infected bursa but isn’t always present.
Because the two can be nearly indistinguishable by appearance alone, fluid from the bursa sometimes needs to be drawn and tested to confirm infection. If the redness is spreading, the pain is severe and worsening rapidly, or you have any open skin nearby, those are reasons to get it evaluated promptly.
What Causes the Swelling
A bursa is a small, fluid-filled sac that cushions the space between bone and soft tissue. At the back of the heel, you have two bursas: one between the Achilles tendon and the heel bone (the retrocalcaneal bursa), and one between the tendon and the skin. When either gets irritated, it fills with extra fluid and swells.
The most common triggers are shoes with stiff, unyielding heel counters that press into the back of the heel repeatedly. Running with a heavy heel strike pattern also increases impact forces on this area. A prominent heel bone, tight calf muscles, or a sudden increase in activity can all contribute. The swelling you see is essentially the bursa doing its job (protecting the tendon) but becoming overwhelmed by too much friction or pressure.
How It Differs From Other Heel Problems
Heel bursitis is sometimes confused with Achilles tendinitis or plantar fasciitis because all three cause heel pain. The location of swelling helps you tell them apart. Bursitis produces a visible bump or puffiness right at the back of the heel, at or just above where the tendon meets the bone. Achilles tendinitis causes thickening and tenderness along the tendon itself, usually a few centimeters above the heel. Plantar fasciitis causes pain on the bottom of the heel, typically worst with the first steps in the morning, and rarely produces any visible swelling at the back.
If you’re looking at the back of your heel and see a noticeable soft lump with redness or warmth, that pattern points toward bursitis rather than a tendon or fascia problem.
Recovery and Reducing the Swelling
With conservative treatment, retrocalcaneal bursitis typically improves within four to six weeks. Recovery can take longer if a bone spur or Haglund’s deformity is mechanically irritating the area, since the structural trigger doesn’t go away on its own.
The most effective first step is removing the source of friction. Switching to shoes with a soft or open heel counter, or using backless shoes temporarily, takes pressure off the inflamed bursa. Orthotic inserts or a small heel lift can shift your foot’s position inside the shoe to reduce rubbing. Ice applied to the back of the heel for 15 to 20 minutes helps bring down acute swelling, and anti-inflammatory medication can manage both pain and visible inflammation.
You’ll know it’s improving when the bump feels less full, the redness fades, and pressing on the area becomes less tender. The swelling typically decreases gradually rather than disappearing overnight. If the bump persists beyond a couple of months despite these changes, imaging with ultrasound can confirm the diagnosis and measure how much fluid remains in the bursa. In healthy individuals, the retrocalcaneal bursa is less than a millimeter thick. In active bursitis, it swells well beyond that, and ultrasound can pick up increased blood flow to the area, confirming ongoing inflammation.