3. Bursitis
The bursa is fluid-filled fibrous sacs found in the heel that lubricate the ankle joint. The retrocalcaneal bursa, lies between the Achilles tendon and the heel bone, while the retroachilles bursa seats between the Achilles tendon and the skin. Both of these fibrous sacs are at risk of inflammation from various causes.
The most common form of bursitis affects the retroachilles bursa and typically occurs due to wearing shoes that don’t fit your feet properly. The rear of the shoe rubs against the heel, inflaming the retroachilles bursa, producing a bump on the back of the foot at the same height as the upper of your shoe.
The retrocalcaneal bursa is less common and occurs due to inflammation of the heel bone, plantar fascia, or Achilles tendon through impact or trauma. Doctors sometimes drain retroachilles bursa if they become uncomfortable, but most will disappear on their own when the affected individual changes their footwear.
However, the retrocalcaneal bursa is much more challenging to treat and may include the use of anti-inflammatories and painkillers to soothe the inflammatory effects of the condition.