Heel pain is one of the most prevalent musculoskeletal complaints in both the general population and among athletes. The heel — the largest bone in the foot — bears the full weight of the body with every step, making it uniquely vulnerable to a wide range of mechanical, inflammatory, and systemic conditions. Understanding the causes of heel pain is essential not only for effective treatment but also for prevention. This essay explores the primary causes of heel pain, from the most common structural disorders to less frequently recognised systemic and neurological contributors.
Plantar Fasciitis: The Most Common Culprit
Plantar fasciitis is by far the most frequently diagnosed cause of heel pain, accounting for the majority of cases seen in clinical practice. The plantar fascia is a thick band of connective tissue that runs along the bottom of the foot, connecting the heel bone (calcaneus) to the toes. It plays a critical role in supporting the arch and absorbing the shock of walking and running. When this tissue becomes overstressed — through repetitive strain, excessive standing, or sudden increases in physical activity — small tears develop within the fascia, triggering an inflammatory response. The result is a sharp, stabbing pain typically felt at the front of the heel, particularly during the first steps in the morning or after prolonged rest. The pain tends to ease with movement but can return after long periods of standing or physical activity. Risk factors include obesity, flat feet or high arches, wearing unsupportive footwear, and occupations that require extended periods on one’s feet.
Heel Spurs
Heel spurs are bony outgrowths that develop on the underside of the calcaneus, often as a result of long-standing plantar fasciitis. They form in response to repeated stress and calcium deposits along the plantar fascia’s attachment point. Interestingly, many people with heel spurs experience no pain at all, while others suffer significant discomfort. When pain does occur, it is typically a dull, aching sensation that becomes sharper under weight-bearing activities. Heel spurs are diagnosed via X-ray and are most common in middle-aged individuals, athletes, and those with poor footwear or abnormal gait patterns. While they are often conflated with plantar fasciitis, the two conditions are distinct — though they frequently co-occur.
Achilles Tendinopathy
The Achilles tendon, which connects the calf muscles to the heel bone, is the thickest and strongest tendon in the human body — yet it is also among the most injury-prone. Achilles tendinopathy refers to a spectrum of conditions resulting from overuse or degeneration of the tendon. It presents as pain, stiffness, and swelling at the back of the heel, often worsening in the morning or at the beginning of exercise. The condition is particularly common among runners and older athletes, and it can be exacerbated by training too aggressively, wearing worn-out footwear, or having tight calf muscles. If left untreated, Achilles tendinopathy can progress to a partial or complete tendon rupture — a much more serious injury requiring prolonged rehabilitation or surgical repair.
Bursitis
Retrocalcaneal bursitis involves inflammation of the bursa — a small, fluid-filled sac — situated between the Achilles tendon and the heel bone. This bursa functions as a cushion, reducing friction during movement. When it becomes irritated through repetitive impact, direct pressure from footwear, or as a secondary effect of Achilles tendinopathy, it swells and causes pain at the back of the heel. The pain is typically described as a deep ache or burning sensation and is often exacerbated by tight shoes or activities involving repetitive ankle flexion, such as stair climbing and cycling.
Stress Fractures
Stress fractures of the calcaneus are a less common but significant cause of heel pain, particularly in runners, military recruits, and those with osteoporosis or low bone density. Unlike acute fractures resulting from a single traumatic event, stress fractures develop gradually from repetitive loading that exceeds the bone’s capacity to remodel. The pain associated with a calcaneal stress fracture is typically diffuse, worsening progressively with activity and relieved by rest. Diagnosis can be challenging, as stress fractures may not be visible on standard X-rays in the early stages, often requiring MRI or bone scan for confirmation. Left unaddressed, they carry the risk of developing into complete fractures.
Nerve Entrapment and Neurological Causes
Several neurological conditions can mimic or contribute to heel pain. Tarsal tunnel syndrome — analogous to carpal tunnel syndrome in the wrist — involves compression of the tibial nerve as it passes through the tarsal tunnel on the inner side of the ankle. This can cause burning, tingling, or shooting pain that radiates into the heel and sole of the foot. Baxter’s nerve entrapment, involving the inferior calcaneal nerve, is a frequently overlooked cause of chronic heel pain that can be mistaken for plantar fasciitis. Additionally, radiculopathy from lumbar spine pathology — particularly nerve root compression at the L5 or S1 levels — can produce referred pain in the heel, highlighting the importance of a thorough musculoskeletal assessment.
Systemic and Inflammatory Conditions
Heel pain is not always purely mechanical in origin. Several systemic diseases are known to cause or contribute to heel pain, particularly through inflammatory arthropathy. Rheumatoid arthritis and the seronegative spondyloarthropathies — including ankylosing spondylitis, psoriatic arthritis, and reactive arthritis — can all cause enthesitis, which is inflammation at the sites where tendons and ligaments attach to bone. The heel entheses, particularly the attachment of the plantar fascia and Achilles tendon, are common sites for this inflammation. In such cases, heel pain may be accompanied by other joint symptoms, morning stiffness lasting more than an hour, and systemic features such as fatigue or skin changes. Gout, caused by the deposition of uric acid crystals in joints and soft tissues, can also occasionally affect the foot and heel.
Footwear and Biomechanical Factors
Beyond specific pathological conditions, a number of biomechanical and lifestyle factors play an important role in predisposing individuals to heel pain. Wearing shoes with inadequate arch support or excessive heel cushioning can alter the distribution of forces through the foot, placing undue stress on the heel structures. Gait abnormalities such as overpronation (inward rolling of the foot) or supination can similarly increase loading at the heel. Being overweight or obese significantly increases the mechanical burden placed on the heel with each step, accelerating the onset of conditions such as plantar fasciitis and stress fractures. Prolonged standing on hard surfaces — common in professions such as nursing, hospitality, and retail — compounds these effects over time.
Heel pain is a multifaceted condition with a broad spectrum of potential causes, ranging from mechanical overuse injuries to inflammatory arthritis and neurological entrapment syndromes. Plantar fasciitis remains the most prevalent diagnosis, but clinicians and patients alike must remain alert to less common aetiologies that may present similarly. Effective management depends on accurate diagnosis, which in turn requires a thorough understanding of the anatomical structures involved and the diverse ways in which they can be affected. Addressing contributing factors — such as footwear, body weight, and activity levels — alongside targeted treatment is key to achieving lasting relief from heel pain.