Your ankle is formed by the coming together of four different bones. The ankle bone itself is called the talus.

Imagine you’re wearing a pair of sneakers. The talus would be located near the top of the sneaker’s tongue.

The talus fits into three other bones: the tibia, fibula, and calcaneus. The two bones of your lower leg (tibia and fibula) form sockets that cup around the upper part of the talus. The lower part of the talus fits into the heel bone (calcaneus).

Ankle bursa

A bursa is a small fluid-filled sac that cushions and lubricates bones when they move.

There is a bursa located at the back of your foot, between your heel bone (calcaneus) and your Achilles tendon. This bursa cushions and lubricates the ankle joint. It’s called the retrocalcaneal bursa.

When the retrocalcaneal bursa becomes inflamed, the condition is called either retrocalcaneal bursitis or anterior Achilles tendon bursitis.

Ankle bursitis occurs when bursae become inflamed. This can happen under stresses from movement or from an impact injury, or even pressure on certain spots from ill-fitting shoes.

Here are some of the things that can cause inflamed bursae:

  • overuse or strain on the ankle from repetitive physical activity, including walking, jumping, or running
  • running uphill without proper stretching or training
  • poorly fitting shoes
  • previous injury
  • ankle arthritis
  • gout
  • infection or septic bursitis
  • rheumatoid arthritis
  • enlargement of the heel bone, known as Haglund’s deformity
  • a direct hit to the area

Sometimes stress on the ankle can cause a new bursa to form beneath the skin surrounding other parts of the ankle joint. These bursae can also become inflamed, causing ankle bursitis.

The names and common locations for these additional bursae are:

  • Subcutaneous calcaneal bursa. This forms at the back of the heel, below the retrocalcaneal bursa. Inflammation of this bursa mainly occurs in young women wearing high heels. It’s also called posterior Achilles tendon bursitis.
  • Subcutaneous bursa of medial malleolus. This bursa forms at the protrusion of the inside of the ankle where the shin bone (tibia) ends.

Symptoms may develop slowly. You’ll likely feel pain around the heel. Some other things to look for are:

  • swelling of soft tissue at the top of the heel bone
  • pain when pressure is applied to the back of the heel or when you flex your foot
  • pain when standing on tiptoes or when leaning back on your heels
  • limping when walking to avoid the pain of putting full weight on your ankle
  • redness (with posterior Achilles tendon bursitis)
  • fever or chills, which may be signs of an infection

Ankle bursitis is diagnosed with a physical examination. Your doctor will look for visible inflammation and feel the ankle for sensitivity to movement.

An X-ray may be used to rule out fracture or dislocation of the ankle joint. The soft tissues of the bursa don’t show up on an X-ray.

Your doctor may order an MRI scan to see if the bursa is swollen.

If your doctor suspects an infection, they may need to use a syringe to collect fluid from the bursa. This is done with an anesthetic, and may be guided by CAT scan, X-ray, or ultrasound imaging.

Ankle bursitis and Achilles tendinopathy have overlapping symptoms, and it’s possible to have both at the same time. It’s important to see a healthcare provider to identify the source of your symptoms.

Treatment begins with conservative measures:

  • Ice and rest your ankle for the first few days after the start of symptoms to reduce inflammation.
  • Take NSAIDs such as ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn), or prescription pain relievers.
  • Wear roomy, comfortable shoes.
  • Consider using shoe inserts to prevent friction at the inflamed points.

Read about making and using a cold compress.

Your doctor may prescribe physical therapy to help reduce the pain in early stages of treatment and later to aid recovery.

If the ankle doesn’t respond to these measures, your doctor may recommend injection of the bursa with a corticosteroid to help calm the inflammation. This procedure will most likely be done with a local anesthetic.

Some doctors have reported success in improving the accuracy of corticosteroid injection by using ultrasound imaging to guide the placement of the needle.

If tests show an infection is present (septic bursitis), your doctor will prescribe appropriate antibiotics.

These are the most important things you can do to prevent ankle bursitis:

  • Always stretch and warm up before exercise, any form of sports, or strenuous activity.
  • Wear proper footwear that gives you support and isn’t too tight or too loose.
  • Avoid sudden jerky motions and sudden increase in weights while working out.

These precautions are important if you’re increasing your activity level and time spent on your feet. They’re especially important if you play a sport that involves high impact on your feet, like basketball, soccer, tennis, and running. They also apply to weight training for the legs.

If you develop an ankle bursitis, take care of it. Don’t ignore the pain — respect it. It’s telling you that something is wrong. Treating it early will get you back on your feet and back to your favorite activity much faster than ignoring it. Conservative treatment like rest and anti-inflammatories is much more likely to work if you act right away.