Achilles bursitis is inflammation of one of the small fluid-filled sacs (bursae) near where your Achilles tendon meets your heel bone. It causes pain, swelling, and tenderness at the back of the heel, and it’s one of the most common reasons people develop persistent heel pain that worsens with activity or tight shoes. Though it’s often confused with Achilles tendon problems, bursitis is a distinct condition with its own causes and treatment approach.
Two Types of Achilles Bursitis
There are two bursae near the Achilles tendon, and either one can become inflamed. The type you have affects where exactly the pain shows up and what tends to trigger it.
The first is the retrocalcaneal bursa, which sits in the small space between the back of your heel bone and the Achilles tendon. This is the deeper of the two bursae and the one more commonly involved in clinical cases. It acts as a cushion that reduces friction when you flex your foot. When this bursa swells, pain tends to concentrate deep in the back of the heel, and it often gets worse when you push off the ground while walking or running. This form is sometimes called anterior Achilles tendon bursitis because the bursa sits in front of the tendon.
The second is the subcutaneous calcaneal bursa (also called the superficial or posterior bursa), which develops between the skin and the tendon or heel bone. Unlike the retrocalcaneal bursa, this one isn’t always present at birth. It often forms over time as an acquired response to repeated friction, typically from shoe pressure. Posterior Achilles tendon bursitis starts with redness and warmth at the surface of the heel. Over several months, the irritated area can form a visible, tender nodule. If the irritation continues long enough, that nodule may harden and become scar-like.
What Causes It
The most straightforward cause is mechanical irritation. Shoes with rigid heel counters or high backs press directly against the bursae, especially during repetitive motion like walking or running. Over time, this compression triggers inflammation. People with a naturally prominent heel bone are particularly vulnerable. This bony prominence, known as a Haglund deformity, creates extra pressure in the space where the retrocalcaneal bursa sits. A foot shape with a high arch and inward-tilting heel (cavovarus alignment) makes the problem worse by increasing stress on that area.
Overuse is another common trigger. Runners, hikers, and anyone who suddenly increases their activity level can develop bursitis from repetitive loading of the heel. The bursa that normally cushions movement becomes overwhelmed and swells with excess fluid.
Achilles bursitis can also develop without any physical trauma. Several inflammatory conditions affect the bursae directly. Rheumatoid arthritis is one: research has shown that retrocalcaneal bursitis frequently precedes or accompanies Achilles tendon inflammation in the early phases of the disease, suggesting the bursa’s lining is one of the first structures affected. Spondyloarthritis, a group of inflammatory conditions affecting the spine and joints, is closely associated with inflammation at tendon-to-bone attachment points, including the Achilles region. Psoriatic arthritis and gout can also cause bursitis in this area.
Symptoms and How It Feels
The hallmark symptoms are pain, swelling, and warmth at the back of the heel. Many people first notice it when putting on shoes or walking uphill. Standing on your toes typically increases the pain because this position compresses the bursa between the tendon and bone.
When the retrocalcaneal (deep) bursa is involved, swelling often starts at the back of the heel and, as it enlarges, spreads sideways to both sides. You may notice the area around your heel looks puffy compared to the other foot. Walking becomes uncomfortable, and wearing closed-back shoes can feel unbearable.
With the superficial type, the skin itself may become red and irritated first. The friction point where your shoe rubs can wear away the top layer of skin before the deeper inflammation becomes obvious. Over time, a visible bump forms that is soft and tender to the touch.
How It Differs From Achilles Tendinopathy
Achilles bursitis and Achilles tendinopathy can feel similar since they both cause pain at the back of the heel. But they’re different conditions affecting different structures. In bursitis, the problem is an inflamed, fluid-filled sac. In tendinopathy, the tendon itself is damaged or degenerating.
One key distinguishing feature is pressure within the retrocalcaneal space. Research measuring pressure inside the bursa found that people with retrocalcaneal bursitis had significantly elevated resting pressure (averaging around 30 mmHg), while those with Achilles tendinopathy actually had slightly negative pressure in the same space. As the ankle is flexed upward, pressure rises in both conditions, but the increase is substantially greater in bursitis. This is why dorsiflexion, bending your foot toward your shin, tends to be especially painful with bursitis.
In practical terms, bursitis pain is usually most noticeable with direct pressure on the heel (like from a shoe) and when flexing the foot. Tendinopathy pain tends to be felt more within the tendon itself, often a few centimeters above the heel, and worsens with loading activities like running or jumping. Your doctor can use ultrasound imaging to confirm the diagnosis by looking for fluid accumulation in the bursa and any thickening of the surrounding tissue.
Treatment Without Surgery
Most people with Achilles bursitis improve without surgery. Around 89% of patients with related insertional Achilles problems respond to nonsurgical treatment, so conservative measures are the standard starting point.
The first and most immediate step is reducing the irritation. Switching to open-backed shoes or using soft padding around the heel counter can take pressure off the bursa. Heel lifts placed inside your shoes shift the angle of your foot slightly, reducing compression on the retrocalcaneal space. Ice applied to the area for 15 to 20 minutes several times a day helps control swelling in the early stages.
Stretching the calf muscles is a core part of recovery because tight calves increase tension on the Achilles tendon, which in turn compresses the bursa. A standard program recommended by the American Academy of Orthopaedic Surgeons runs four to six weeks and includes two main stretches done six to seven days per week:
- Straight-knee heel cord stretch: Stand facing a wall with your affected leg straight behind you, heel flat on the floor. Press your hips forward until you feel a stretch in your calf. Hold 30 seconds, rest 30 seconds, and repeat for two sets of 10.
- Bent-knee heel cord stretch: Same position, but with a slight bend in the back knee. This targets the deeper calf muscle (the soleus). Same hold and repetition pattern.
- Towel stretch: Sit with your leg extended, loop a towel around the ball of your foot, and gently pull it toward you with a straight knee. Hold 30 seconds, rest 30 seconds, two sets of 10.
As pain allows, single-leg calf raises help rebuild strength. Stand on your affected foot, rise onto your toes as high as you can, then slowly lower back down. Two sets of 10, six to seven days per week. Start with both feet if single-leg raises are too painful initially.
Steroid Injections: Benefits and Risks
Corticosteroid injections into the bursa are sometimes used when stretching, ice, and shoe changes aren’t enough. The injection delivers a powerful anti-inflammatory directly to the swollen tissue and can provide significant relief. However, the Achilles tendon sits dangerously close to the injection site, and this proximity creates real risk.
Corticosteroids can trigger a degenerative process in tendons. They inhibit collagen production and impair local blood supply, weakening the tendon tissue. Case reports document complete Achilles tendon ruptures following steroid injections intended for the bursa. Because of this, steroid injections directly into or near the Achilles tendon are rarely performed today. When injections are used for bursitis, they should be performed under ultrasound guidance, which allows the clinician to visualize the needle tip and place the medication precisely inside the bursa, avoiding the tendon.
When Surgery Becomes an Option
Surgery is reserved for cases that don’t respond to several months of conservative treatment. The procedure typically involves removing the inflamed bursa (bursectomy) and, when a Haglund deformity is present, shaving down the bony prominence on the heel to eliminate the source of friction. If the Achilles tendon itself has sustained damage from prolonged irritation, the surgeon may clean up the damaged tissue at the same time.
Recovery timelines vary by surgical approach. In one study comparing two techniques, patients who had surgery through a tendon-splitting approach returned to normal function in a median of about four months, with a range of three to 13 months. Those treated with a lateral (side) approach took a median of roughly six and a half months, ranging from four to 20 months. Return to sports took slightly longer: around five to six and a half months on average, though some patients needed well over a year. The tendon-splitting approach showed faster recovery to normal daily activities, though both techniques produced similar timelines for returning to sport.
These are meaningful recovery windows. If you’re an active person weighing surgery, planning for at least four to six months before resuming full activity is realistic, with the understanding that some cases take considerably longer.