That nagging pain at the back of your heel that flares when you put on shoes, push off the ground, or climb stairs is easy to dismiss as a minor irritation. But patients who come in describing a dull ache, a sharp burning sensation, or a lump at the back of the heel that was not there before are often dealing with something more specific. Many of them have already searched their symptoms and landed on Achilles tendonitis (or Achilles tendinitis) as the likely culprit. Sometimes they are right. But a meaningful number of those patients are actually dealing with Achilles tendon bursitis, or a combination of both conditions, and the distinction between Achilles tendon bursitis vs. tendonitis matters because the treatment paths are not identical. Proper diagnosis through diagnostic tests such as MRI scans and physical assessment is essential to determine whether the inflamed or infected bursa or the large tendon itself is the injured area.
This is one of the first things our Dallas foot and ankle specialist Christopher Sakowski, MD, works through during an evaluation. The location of pain, how it behaves with activity and rest, what shows up on imaging such as MRI scans or ultrasound, and whether there is a structural issue like a Haglund deformity involved all factor into an accurate diagnosis of developing Achilles tendon bursitis or insertional Achilles tendinitis. Getting that diagnosis right from the start is what leads to a treatment plan that actually works, including initial treatment and treatment options like non-surgical treatment or a surgical procedure if non-surgical treatment fails to resolve pain and reduce inflammation.
The Anatomy Behind Both Conditions
To understand the difference between these two conditions, you need a clear picture of what is happening in the Achilles region.
The Achilles tendon is the largest and strongest tendon in the body. It connects the gastrocnemius and soleus muscles of the calf to the calcaneus, which is the heel bone. Every time you push off the ground when walking, running, or climbing stairs, the Achilles tendon is under load. Over a lifetime of activity, that adds up to an enormous amount of cumulative stress.
At the point where the Achilles tendon meets the heel bone, there are two small fluid-filled sacs called bursae. Their job is to reduce friction by containing lubricating fluid and cushion the tendon as it moves, which limits ankle movement and helps prevent injury. The one most relevant to this discussion is the retrocalcaneal bursa, which sits between the Achilles tendon and the calcaneus. There is also a subcutaneous bursa on the surface side of the tendon, just under the skin at the back of the heel.
When the tendon itself becomes irritated and inflamed, that is tendonitis. When one of the bursae becomes inflamed, that is bursitis. Both can happen at the same time, which is part of what makes diagnosis more nuanced than a quick symptom check online.
Where Each Condition Hurts
The location of pain is one of the most useful clinical clues for distinguishing between these two conditions.
Achilles tendonitis typically produces pain along the body of the tendon, anywhere from an inch or two above the heel bone up into the mid-portion of the tendon. Insertional Achilles tendonitis, a specific subtype, causes pain right at the point where the tendon attaches to the heel bone. Both subtypes tend to be worse with activity, particularly during the first few minutes of exercise, and may improve as the tendon warms up, only to return after you stop.
Retrocalcaneal bursitis produces pain that is more localized to the very back of the heel, often in the small recess just in front of where the tendon inserts. Patients frequently describe it as a deep ache rather than a surface-level burn. A common symptom is visible swelling in this area. Squeezing the sides of the heel at that location is often painful, and wearing shoes with a firm heel counter, the rigid back portion of a shoe, tends to aggravate it significantly. That shoe irritation pattern is a strong clinical indicator. This painful condition commonly occurs due to excessive repetitive motion or excessive walking, which leads to inflammation of the retrocalcaneal bursa.
When both conditions are present simultaneously, the pain can feel more diffuse and harder to localize, which is one reason imaging plays an important role in confirming the diagnosis.
The Role of Imaging
A physical examination by an experienced specialist is the starting point, but imaging provides detail that examination alone cannot.
Ultrasound is particularly useful for evaluating soft tissue structures in real time. It can visualize tendon thickening, fiber disruption, bursal fluid accumulation, and calcification at the tendon insertion. Doctor Sakowski can use ultrasound to directly compare the appearance of the affected side to the healthy side and identify exactly which structures are involved. It is also useful because it can be performed dynamically, meaning we can observe how the tendon and bursa behave during movement.
MRI provides a more detailed cross-sectional view of the entire Achilles region. It can identify degenerative changes within the tendon that are not visible on ultrasound, map the extent of bursal inflammation, and detect any partial tearing or Achilles tendon rupture. For patients where the clinical picture is complex or where conservative treatment, including common treatments like rest and physical therapy, has not produced improvement, MRI often clarifies what is driving the problem and helps confirm that Achilles tendon bursitis is diagnosed accurately to enhance healing and reduce swelling.
X-ray does not show soft tissue directly, but it is valuable for identifying bony changes. This is especially relevant when a Haglund deformity is suspected.
The Haglund Deformity Connection
This is a detail that surprises many patients. A significant number of people who develop retrocalcaneal bursitis have an underlying structural issue called a Haglund deformity, sometimes referred to as a “pump bump.” This is a bony prominence on the posterosuperior aspect of the calcaneus, the upper back corner of the heel bone. When the Achilles tendon moves over this prominence with each step, it creates repetitive mechanical irritation against the retrocalcaneal bursa.
Haglund deformity is often hereditary, though it is also associated with certain foot types, including high arches and tight heel cords. Wearing rigid-backed footwear and improper footwear accelerates the irritation. Many patients with Haglund deformity also develop concurrent insertional Achilles tendonitis because the same mechanical forces that inflame the bursa also stress the tendon at its insertion point, especially when patients suddenly increase physical activity. This condition affects the lower leg and calf muscles, and pain increases with physical activity. Proper form and observing proper form during exercise can help reduce irritation, but if not managed, Achilles tendon bursitis includes symptoms that worsen over time.
This is why treatment planning for bursitis cannot simply address the inflammation in isolation. If the underlying bony prominence is not accounted for, symptoms are likely to return. That structural consideration shapes both the conservative and surgical approach.
Where Treatment Overlaps
There is meaningful overlap in how both conditions are initially managed, which is part of why the distinction between them sometimes gets glossed over in early treatment.
For both Achilles tendonitis and retrocalcaneal bursitis, the initial approach typically includes:
Activity modification: Reducing or temporarily stopping the activities that are aggravating the condition. This does not always mean complete rest, but it does mean pulling back on high-impact loading.
Footwear changes: Switching to shoes with a softer heel counter or a slight heel lift reduces stress on both the tendon and the bursa. Open-backed footwear can provide immediate relief for bursitis in particular.
Physical therapy: Eccentric calf strengthening is well-supported in the literature for Achilles tendonitis and plays a role in bursitis management as well. A structured PT program addresses both the flexibility and strength deficits that contribute to Achilles region pain.
Anti-inflammatory measures: Ice packs, oral anti-inflammatory medications, and in some cases targeted corticosteroid injections can reduce acute inflammation. Corticosteroid injections require careful consideration near the Achilles tendon given the risk of tendon weakening, and this is a conversation Dr. Sakowski has directly with patients when it comes up. A physical therapist often guides rehabilitation to restore mobility and function effectively.
Where Treatment Diverges
This is where an accurate diagnosis makes a real difference.
For Achilles tendonitis, particularly mid-substance tendonitis, the focus of treatment is on tendon remodeling and load management. Platelet-rich plasma (PRP) injections have shown promise for tendon degeneration that has not responded to physical therapy. The goal is to stimulate the tendon’s healing response and restore normal tissue structure. In cases where there is a significant partial tear or chronic degeneration that has not responded to conservative care, surgical debridement or repair becomes a consideration.
For retrocalcaneal bursitis, particularly when a Haglund deformity is present, conservative measures have a ceiling. If the bony prominence is there, it will continue to mechanically irritate the bursa regardless of how much inflammation is reduced with other treatments such as ice packs, rest, and anti-inflammatory medications. Patients who do not improve with a full course of conservative management, typically several months of consistent treatment, become candidates for surgical intervention. That surgery involves removing the inflamed bursa (bursectomy) and, when indicated, resecting the Haglund prominence to eliminate the source of mechanical irritation. This is done as part of our broader foot surgery services and can often be performed using minimally invasive techniques that reduce recovery time. Accurate Achilles tendon bursitis diagnosed through imaging like MRI helps guide this decision.
The American Academy of Orthopaedic Surgeons has a thorough overview of Achilles tendon conditions and their management, which is a useful reference for patients who want to read further on the subject.
Surgical Considerations for Bursitis
When surgery is warranted for retrocalcaneal bursitis, the procedure addresses multiple problems at once. The inflamed bursal tissue is excised. If there is a Haglund deformity, the bony prominence on the calcaneus is carefully removed. If there is concurrent insertional Achilles tendonitis with calcification or degeneration at the tendon attachment, that is addressed at the same time.
Recovery from this type of surgery is something Dr. Sakowski discusses in detail with every patient before they make a decision. His protocol focuses on getting patients moving as early as safely possible. After the incisions are given two weeks to heal in a splint, patients transition to a boot and begin walking with physical therapy starting right away. That early mobilization approach is intentional. Prolonged immobilization is not always the right answer for tendon and soft tissue healing, and getting the calf and foot moving early supports a better functional outcome.
The right candidate for surgery is someone who has genuinely exhausted conservative options over a meaningful period of time and whose imaging confirms a structural problem like a Haglund deformity that will not resolve on its own. Dr. Sakowski is straightforward about that distinction. When surgery, such as a bursectomy or bony prominence resection, is the right answer, he will tell you clearly. When it is not, he will tell you that too.
Frequently Asked Questions
See Dr. Sakowski About Your Heel Pain
Posterior heel pain that has not responded to rest or basic treatment deserves a proper evaluation. The difference between bursitis and tendonitis is not always obvious from symptoms alone, and treating the wrong condition, or missing an underlying structural issue like a Haglund deformity, means going through weeks of treatment without getting better.
Dr. Sakowski takes the time to walk through your imaging with you, explain exactly what is happening, and lay out every option before any decision is made. That is how it works at our practice. If you are ready to get a clear answer and a real plan, schedule an appointment today.
Written by Christopher Sakowski, MD
Dr. Sakowski is a board-certified orthopedic foot and ankle specialist. A native of Arlington, Texas, he completed his fellowship training at the Institute for Foot and Ankle Reconstruction at Mercy Hospital in Baltimore and has been recognized as a Best Doctor in Dallas and Collin County every year from 2020 through 2026. He sees patients in Dallas and Plano and serves as Team Physician for Lake Highlands High School. Outside of medicine, he enjoys cooking, golfing, fishing, and time with his wife and two children.