What Is Bursitis of the Foot? Causes, Symptoms & Treatment

Bursitis of the foot is inflammation of one or more bursae, the small fluid-filled sacs that cushion bones, tendons, and ligaments where they move against each other. The foot contains several of these sacs in predictable locations, and when any of them swells from overuse, pressure, or disease, the result is localized pain that can make walking miserable. Though it shares symptoms with better-known conditions like plantar fasciitis and Achilles tendinopathy, foot bursitis is a distinct problem with its own anatomy, triggers, and treatment path.

Where Bursae Sit in the Foot

Not all foot bursitis is the same, because the foot has bursae in several different spots, each prone to trouble for different reasons. The most commonly discussed is the retrocalcaneal bursa, which sits between the heel bone and the Achilles tendon. When this sac becomes inflamed and enlarged, every push-off step compresses it against the bone.¹ This is what most people mean when they say “heel bursitis.”

The forefoot has its own set. Inter-metatarsal bursae lie between the metatarsal heads (the ball-of-foot bones), above the ligament that connects them. These become irritated from excessive friction or pressure from the surrounding tissues. Separately, adventitial plantar bursae can develop in the soft tissues beneath the metatarsal heads from repeated shearing between the bones and the weight-bearing surface of the foot.² Then there is the subcalcaneal bursa, located under the heel bone, which produces pain in the central or slightly lateral part of the heel rather than at the back.³

A less obvious category is adventitious bursae. These are not part of normal anatomy; they form over time in areas of chronic friction, typically under bony prominences. In people who have lost protective sensation in their feet, adventitious bursae can develop beneath chronic wounds and may interfere with healing.⁴ Understanding where in the foot the problem sits is the first step toward figuring out what is causing it.

What Causes Foot Bursitis

The most straightforward trigger is mechanical. Repetitive impact from excessive walking, jumping, or running creates a steady stream of minor trauma to the bursae. Shoes that dig into the back of the heel are a primary cause of calcaneal bursitis, and footwear that is too tight can compress the retrocalcaneal bursa directly against the bone. Activities that involve repeated push-off movements are especially risky because they force the bursa into a narrow space between the Achilles tendon and the heel bone with each stride.

Foot structure also plays a role. A tight Achilles tendon, a high arch, and hereditary bone shape have all been suggested as contributing factors in Haglund’s syndrome, a condition where a bony prominence on the back of the heel irritates the retrocalcaneal bursa.⁵ When the bone is naturally prominent, even moderate activity can produce enough friction to inflame the overlying bursa.

Systemic diseases are the other major driver. Rheumatoid arthritis in particular is closely linked to forefoot bursitis. A large MRI-based study found that inter-metatarsal bursitis was present in roughly seven out of ten early rheumatoid arthritis patients, and the association held even after accounting for age, sex, BMI, and other inflammatory markers.⁶ Gout can also produce bursal inflammation. In these cases, treating the underlying disease is as important as treating the bursa itself.

What Foot Bursitis Feels Like

Symptoms depend on which bursa is involved, but some features are common across all types. The hallmark is localized pain that worsens with pressure or movement. The area over the inflamed bursa is typically tender to the touch, and you may notice swelling or warmth. The pain tends to build gradually over days or weeks rather than striking suddenly.

Retrocalcaneal bursitis produces pain at the back of the heel, just above where the Achilles tendon attaches to the bone. It often feels worst when you first start walking after rest and when wearing shoes with a rigid heel counter. Squeezing the sides of the heel may reproduce the pain, which helps distinguish it from Achilles tendon problems. Subcalcaneal bursitis, by contrast, causes pain under the heel, centered slightly behind and to the outside of where plantar fasciitis tends to hurt.³

Forefoot bursitis, whether inter-metatarsal or plantar, shows up as pain in the ball of the foot, sometimes with a sensation of walking on a lump. Because inter-metatarsal bursitis sits in the same anatomical neighborhood as Morton’s neuroma, the two can feel remarkably similar. A study that looked at patients with pain between the metatarsals found that even ultrasound could not reliably tell bursitis apart from neuroma in most cases.⁷ The overlap is real, and it has practical consequences for how the problem gets evaluated.

How Foot Bursitis Is Diagnosed

Most cases start with a physical exam. A clinician will press on the suspected area and move the foot to see which positions reproduce the pain. For heel bursitis, the examiner may squeeze the sides of the heel or dorsiflex the ankle to compress the retrocalcaneal bursa. For forefoot bursitis, pressing between the metatarsal heads or squeezing the forefoot from side to side can provoke symptoms. These hands-on tests give a good first impression, but imaging is often needed to confirm what is going on underneath.

Ultrasound and MRI are the main imaging tools. For forefoot bursitis in particular, the agreement between ultrasound and MRI findings is high, and both methods are reliable across different examiners.⁸ Ultrasound is cheaper, faster, and allows the clinician to see the bursa in real time while pressing on it. MRI provides more anatomical detail and is better at revealing bone edema, tendon damage, or other problems hiding alongside the bursitis.

The diagnostic challenge is less about confirming the bursa is inflamed and more about ruling out conditions that sit right next door. Retrocalcaneal bursitis and Achilles tendinopathy share the back-of-the-heel location, but research has shown they are physiologically distinct. Patients with retrocalcaneal bursitis have significantly elevated pressure inside the bursa even at rest, while those with Achilles tendinopathy do not, supporting the idea that bursitis involves a true impingement problem rather than a tendon-degeneration problem.⁹ At the bottom of the heel, subcalcaneal bursitis can coexist with plantar fasciitis; one case report documented both present together, with degeneration of the plantar fascia possibly related to the development of the bursitis.¹⁰ The conditions are not mutually exclusive, which is one reason heel pain can be so stubborn.

Conservative Treatment

The first-line approach to foot bursitis is non-surgical, and for many people it works well. A retrospective review of patients with both posterior and subcalcaneal bursitis found that average pain scores dropped by about 4 points on a 10-point scale after conservative treatment, with more than half reporting complete symptom resolution.³ The treatments patients found most helpful were padding and orthotics, each rated highly effective, followed by icing and anti-inflammatory medications.

The specifics depend on which bursa is inflamed. For retrocalcaneal bursitis, switching to shoes with a softer or lower heel counter removes the main source of compression. Heel lifts can reduce the angle of the ankle and take pressure off the bursa. Stretching the Achilles tendon and calf muscles is a standard recommendation because a tight tendon increases the mechanical squeeze on the bursa with every step. For forefoot bursitis, metatarsal pads that redistribute pressure away from the inflamed area and shoes with a wider toe box can provide relief.

Corticosteroid injections are a step up from basic conservative measures. For retrocalcaneal bursitis, image-guided injections into the bursa produced a good or excellent response in about 63% of patients at short-term follow-up.¹¹ That success rate is decent but not overwhelming, and the approach carries risk. In the same study, about 14% of patients eventually went on to have surgery anyway, and four patients experienced Achilles tendon ruptures within two months of the injection. Each of those ruptures was preceded by an acute injury, but the steroid injection may have weakened the tendon enough to make it vulnerable. The presence of active blood flow (Doppler signal) in the bursa before the injection was a strong predictor of eventually needing surgery, which could help clinicians identify patients who are less likely to get lasting relief from an injection.

When Surgery Enters the Picture

Surgery is reserved for cases that do not respond to months of conservative care. For retrocalcaneal bursitis, the standard procedure involves removing the inflamed bursa and shaving down the bony prominence on the back of the heel to create more space for the Achilles tendon. Resecting enough bone is considered essential for a good outcome regardless of the surgical technique used.¹²

Timing matters. An older but informative study of 43 heels that underwent surgical decompression found that overall, about half were cured and another 20% improved. But when surgery was performed within the first year of symptoms, the combined cure-or-improvement rate jumped to 92%.¹³ Waiting years while the condition becomes more chronic appears to worsen surgical outcomes. This is worth knowing if you are the type to push through heel pain for extended periods before seeking help.

Endoscopic (minimally invasive) surgery has become the preferred approach at many centers. A review of the surgical literature concluded that endoscopic techniques are superior to open surgery for retrocalcaneal bursitis, and a long-term follow-up study of endoscopic calcaneoplasty reported high patient satisfaction and good functional outcomes years after the procedure.¹⁴ The smaller incisions mean less damage to the surrounding soft tissue, faster recovery, and a lower risk of wound complications. That said, the overall quality of evidence for foot bursitis surgery remains limited, with most studies being retrospective case series rather than head-to-head trials.

It is also worth noting that outcomes differ depending on what exactly is being treated. A study comparing surgical decompression for pure retrocalcaneal bursitis versus Achilles insertional tendinosis with a bone spur found that patients with bursitis alone recovered faster, reported higher satisfaction, and had fewer shoe-wear restrictions afterward.¹⁵ If your imaging shows bursitis without significant tendon disease, that is a relatively favorable surgical scenario.

Septic Bursitis and When to Worry

Most foot bursitis is non-infectious, driven by mechanical stress or systemic inflammation. But bursae can become infected, and septic bursitis is a different clinical animal. Classic signs that an inflamed bursa has become infected include fever, pronounced tenderness, redness spreading beyond the bursa into the surrounding skin, and any break in the skin overlying the bursa. Lab findings that distinguish septic from non-septic bursitis include a high white blood cell count in the bursal fluid and a low ratio of sugar in the bursal fluid compared to the blood.¹⁶

Septic bursitis requires antibiotics rather than anti-inflammatories. Research has found that the longer an infection has been present before treatment starts, the longer the course of antibiotics needed to clear the fluid. On average, successful therapy took about 12 days. The most common culprit is Staphylococcus aureus, and a drug active against penicillin-resistant strains is recommended as the first choice.¹⁶ If you develop worsening redness, warmth, and fever around a swollen bursa, especially if there is a nearby cut or blister, do not treat it as a simple overuse problem. It needs medical evaluation promptly.

The Rheumatoid Arthritis Connection

Forefoot bursitis deserves special attention in the context of rheumatoid arthritis because it can be one of the earliest signs of the disease. The MRI study mentioned earlier found that inter-metatarsal bursitis had a sensitivity of about 69% for early rheumatoid arthritis, meaning it was present in roughly two-thirds of patients. It also had reasonable specificity: about 70% when compared to other forms of arthritis and 84% when compared to healthy controls.⁶ Submetatarsal bursitis was less common in rheumatoid arthritis, but when present it was highly specific for the disease (97% specificity compared to healthy controls).

What this means in practical terms is that unexplained forefoot bursitis, especially in someone with joint stiffness, fatigue, or swelling elsewhere, is worth investigating further. It can appear before the joints of the hands and wrists show obvious damage, giving doctors a potential early window for treatment. Rheumatoid arthritis patients already diagnosed should know that ball-of-foot pain is not always just from wearing the wrong shoes; it may reflect disease activity that warrants adjusting medication rather than simply buying new orthotics.

Conditions That Mimic Foot Bursitis

Foot bursitis regularly gets confused with neighboring problems, and the overlap is not always easy to untangle even with imaging. In the forefoot, inter-metatarsal bursitis and Morton’s neuroma produce nearly identical symptoms. Both cause pain between the metatarsal heads, both can feel like a lump underfoot, and both light up on ultrasound in ways that look similar. One diagnostic study found that standard ultrasound was unable to reliably differentiate the two conditions.⁷ MRI may offer more detail, but even then, the two can coexist. The treatment approach overlaps as well, with wider shoes, metatarsal pads, and injections used for both, so in many cases the diagnostic ambiguity does not change immediate management.

At the back of the heel, bursitis, Achilles tendinopathy, and Haglund’s deformity form a trio that can be hard to separate clinically. All three produce posterior heel pain, and two or even all three may be present simultaneously. The pressure-measurement research distinguishing bursitis from tendinopathy is helpful in a research setting but not something clinicians routinely perform. In practice, the combination of physical exam, imaging, and response to initial treatment guides the diagnosis. At the bottom of the heel, subcalcaneal bursitis sits in the differential alongside plantar fasciitis, calcaneal stress fracture, nerve entrapment, and fat-pad degeneration.¹⁰ A key clinical clue is the pain location: subcalcaneal bursitis tends to center more proximally and laterally than plantar fasciitis, which usually hurts right at the inner part of the heel where the fascia attaches.

Adventitious Bursae and Neuropathic Feet

Beyond the bursae you are born with, the body can create new ones. Adventitious bursae develop in areas of chronic friction, usually under bony prominences, as the body’s attempt to protect tissue from repeated mechanical stress. In people with intact sensation this is typically a minor curiosity, but in neuropathic feet, where protective feeling has been lost due to diabetes or another nerve condition, these newly formed bursae can become a serious problem.

When an adventitious bursa forms beneath a chronic wound, it may create a fluid-filled pocket that prevents the wound from healing. Clinical case reviews have documented neuropathic patients with nonhealing wounds that were unexpectedly underlain by adventitious bursae, and treating the bursa was necessary to allow the wound to close.⁴ This is a niche scenario, but it matters for anyone managing diabetic foot ulcers or other chronic wounds on the feet. If a wound refuses to heal despite appropriate wound care, an underlying adventitious bursa is one of the less commonly considered culprits worth investigating with imaging.