When most people think about heel pain, they immediately think of plantar fasciitis or plantar fasciosis. However, not every painful heel originates from the plantar fascia. One of the most commonly overlooked causes of persistent heel pain is calcaneal bone marrow oedema, sometimes referred to as a bone stress reaction within the heel bone.
Bone marrow oedema is not a disease itself. Rather, it is an MRI finding that indicates increased fluid within the bone marrow. In the heel, this usually reflects stress, overload or injury to the calcaneus. The increased fluid represents the bone's response to excessive mechanical loading and may occur before a stress fracture develops.
Unlike plantar fasciosis, which affects the thick band of connective tissue beneath the foot, bone marrow oedema affects the heel bone itself. This distinction is important because the treatment differs significantly. Patients treated only for plantar fasciosis when the primary problem lies within the calcaneus often experience disappointing results because the underlying bone injury has not been recognised.
The symptoms can overlap considerably with plantar fasciosis. Patients commonly describe pain beneath or within the heel, discomfort during prolonged walking or standing and difficulty returning to sport or exercise. However, bone marrow oedema often produces a deeper, less localised pain than plantar fasciosis. Some patients describe the sensation as feeling as though the pain is "inside the heel bone" rather than directly under the sole of the foot.
Pain from bone marrow oedema is also more likely to worsen with continued activity. Whereas many patients with plantar fasciosis gradually warm up after the first few steps, patients with bone marrow oedema often find that the pain progressively increases the longer they remain on their feet. Running, jumping and prolonged walking commonly aggravate the condition because they increase repetitive loading through the calcaneus.
Bone marrow oedema may develop for several reasons. Repetitive overload is one of the most common causes, particularly in runners, athletes and individuals who suddenly increase their activity levels. It may also occur in patients with altered foot biomechanics, following trauma or in association with chronic plantar fasciosis, where longstanding traction on the plantar fascia attachment contributes to increased stress within the heel bone.
Importantly, bone marrow oedema frequently coexists with other causes of heel pain. It is not unusual for a patient to have both plantar fasciosis and calcaneal bone marrow oedema at the same time. In these cases, treating the plantar fascia alone may provide only partial improvement because the painful bone stress reaction remains untreated.
Unlike plantar fasciosis, bone marrow oedema cannot usually be diagnosed with ultrasound. Diagnostic ultrasound is excellent for assessing the plantar fascia, tendons and surrounding soft tissues but cannot visualise changes occurring within the bone marrow. MRI remains the gold standard for identifying bone marrow oedema because it can demonstrate the increased fluid within the calcaneus before structural changes become visible on standard X-rays.
Recognising calcaneal bone marrow oedema is important because the management focuses on reducing stress through the heel bone while allowing the bone to recover. Activity modification, temporary reduction in impact loading, appropriate footwear, rehabilitation and treatment of any contributing biomechanical factors are often required. In some cases, the recovery pathway differs substantially from that used for isolated plantar fasciosis.
The key message is that persistent heel pain is not always caused by the plantar fascia. When symptoms fail to improve as expected or the clinical picture does not fully fit plantar fasciosis, other diagnoses—including calcaneal bone marrow oedema—should be considered. An accurate diagnosis remains the foundation of successful treatment.