Pain in the back of the heel occurs where the Achilles tendon connects to the calcaneus (heel bone). This area is a complex intersection of bone, tendon, and fluid sacs. Because multiple structures converge here, pain can stem from several distinct mechanical issues. Identifying the specific source of discomfort is the first step toward finding relief for this common problem.
Achilles Tendon Pathologies
The Achilles tendon connects the calf muscles to the heel bone, managing immense loads during movement. Overloading the tendon can lead to two primary conditions: Achilles tendinitis or Achilles tendinopathy. Achilles tendinitis is an acute issue characterized by inflammation, often following a sudden increase in activity intensity. This inflammatory response usually presents as pain and swelling near the tendon’s insertion point.
Achilles tendinopathy is a more chronic condition involving degeneration and microtears of the tendon fibers, resulting from sustained, repetitive overuse or persistently tight calf muscles. Both conditions cause noticeable stiffness, especially upon waking or after rest. Pain generally worsens immediately with activity, though it may temporarily improve as the tendon warms up, returning more intensely after the activity is complete.
Retrocalcaneal Bursitis
Pain can also originate from the retrocalcaneal bursa, a small, fluid-filled sac located between the calcaneus and the Achilles tendon. Its function is to reduce friction, allowing the tendon to glide smoothly over the bone during ankle movement.
Retrocalcaneal bursitis occurs when the sac becomes inflamed, usually due to repetitive friction or direct pressure. Ill-fitting or rigid-backed shoes that constantly rub against the bursa are a common cause. Symptoms include swelling, redness, and a deep, aching pain localized just in front of the Achilles tendon insertion. Bursitis pain is often hypersensitive to direct pressure applied to the sides of the heel.
Structural Bony Abnormalities
A bony structural issue can create a mechanical conflict, irritating surrounding soft tissues. Haglund’s Deformity, or “pump bump,” is an abnormal enlargement of the bone at the upper back of the calcaneus. This bony protrusion is often hereditary but may remain asymptomatic until aggravated.
The pain results from mechanical impingement, where the enlarged bone rubs against the Achilles tendon and the retrocalcaneal bursa. This constant friction often causes secondary conditions, such as Achilles tendinitis or retrocalcaneal bursitis. Rigid-backed footwear, like high heels, significantly exacerbates this condition by compressing the soft tissue against the bony prominence.
Causes Specific to Growing Feet
When heel pain occurs in children and adolescents, the cause is often Sever’s Disease, or calcaneal apophysitis. This temporary condition is exclusive to individuals with an open growth plate, typically ages 8 to 14 years. It is an inflammation of the heel bone’s growth plate (apophysis), which is vulnerable cartilage where bone formation is actively occurring.
The pain results from the strong pull of the Achilles tendon on the weaker growth plate during rapid growth. During a growth spurt, the bone lengthens faster than the attached muscles and tendons, increasing tension on the apophysis. Repetitive high-impact activities intensify this traction force, leading to inflammation. This condition is self-limiting and resolves naturally once the growth plate fully fuses into solid bone, typically by the end of adolescence.