Finding a lump or bump on your heel can be disconcerting. The heel (calcaneus) is a complex structure involving bone, tendons, fascia, and specialized fluid-filled sacs, meaning a lump can stem from several different sources. While most growths are benign and represent common orthopedic conditions, understanding the characteristics and location of the mass helps with initial identification. This overview provides general information about the most frequent causes of heel lumps, but it is not a substitute for a medical diagnosis.
Lumps at the Back of the Heel
Lumps forming on the posterior aspect of the heel, near the Achilles tendon insertion, often involve the heel bone or surrounding soft tissues. The most common cause for a hard, fixed lump here is Haglund’s deformity, often nicknamed the “pump bump.” This condition is an abnormal enlargement of the posterior superior corner of the calcaneus (heel bone).
The bony growth is hard to the touch because it is an excess of bone tissue. This structure causes irritation when it rubs against the rigid back of certain footwear, such as skates, stiff boots, or pumps. This constant friction frequently leads to retrocalcaneal bursitis, which is the inflammation of the retrocalcaneal bursa. This bursa is a small, fluid-filled sac situated between the Achilles tendon and the heel bone that normally serves as a cushion.
When the bursa becomes inflamed due to the bony lump, it swells, creating a softer, fluid-filled lump that overlays the hard prominence. This results in a noticeably enlarged area that can be red, warm, and tender to the touch. Individuals with certain foot structures, such as a high arch or a tight Achilles tendon, may be predisposed to developing this issue.
Lumps Under the Heel or Arch
A lump felt on the sole of the foot, under the heel or extending into the arch, typically involves the dense connective tissue known as the plantar fascia. The most frequent mass found here is a plantar fibroma, which presents as a firm nodule in the arch area. Plantar fibromas are fibrous growths composed of connective tissue cells, often feeling like a fixed knot or marble just beneath the skin.
These growths are benign (non-cancerous) and can sometimes develop in multiples, a condition called plantar fibromatosis. The nodule’s size can range significantly, but they are generally slow-growing. They may not cause pain unless they are large enough to press against the ground or footwear during walking. Pain, when present, usually results from mechanical pressure on the nodule.
A completely different type of lump in this region is a deep heel spur, a bony projection that forms on the underside of the heel bone. Unlike the softer plantar fibroma, a heel spur is a hard, fixed outgrowth of the calcaneus. The spur itself may not be the direct source of pain, but the inflammation of surrounding soft tissues caused by the body’s reaction to the spur often leads to chronic discomfort in the sole. These bony spurs are typically deeper and can only be definitively identified through imaging like an X-ray.
Identifying Soft Tissue Swellings and Cysts
Beyond fixed bony or fibrous masses, many heel lumps are soft tissue swellings that can occur anywhere in the foot and ankle. These masses are generally more mobile and are classified by their contents rather than the structure they are attached to. Ganglion cysts are a common example, presenting as firm, fluid-filled sacs that often arise near joints or tendons.
These cysts contain a thick, gelatinous fluid similar to the synovial fluid that lubricates joints and tendons, and they can fluctuate in size. Their attachment point to the tendon sheath or joint capsule is their defining characteristic. Another distinct type of soft tissue mass is a lipoma, a benign tumor composed entirely of mature fat cells.
A lipoma usually feels soft and doughy to the touch and is often highly mobile, easily moving beneath the skin when pressure is applied. These fatty tumors are typically painless unless they grow large enough to compress a nearby nerve. Superficial bursitis, distinct from the retrocalcaneal type, can also produce a soft lump resulting from friction or direct trauma to a bursa located just under the skin. This swelling is characterized by localized warmth and redness.
Traumatic injury can also result in temporary soft tissue lumps, such as a hematoma (a collection of blood outside of blood vessels) or generalized edema. These masses appear rapidly following an impact and usually resolve as the body reabsorbs the fluid or blood. Less common are xanthomas, which are soft, waxy, yellowish lumps that can appear near the Achilles tendon and are often associated with systemic conditions like high cholesterol or diabetes.
When to Seek Professional Medical Advice
While many heel lumps are benign and manageable with conservative care, certain symptoms signal that professional medical evaluation is necessary. Consult a healthcare provider, such as a podiatrist or orthopedic specialist, if the lump is accompanied by severe or rapidly increasing pain that affects your ability to walk. Any lump that grows quickly, changes shape, or appears fixed and immovable should also be examined promptly.
Signs of infection, including increasing redness, warmth, discharge, or a fever, require immediate attention. Pain that persists despite several weeks of rest, ice, and over-the-counter pain relievers suggests the condition is not resolving and requires a formal diagnosis. Persistent pain that wakes you up at night or is present even when you are not bearing weight is a red flag that warrants timely investigation.
A medical professional can use imaging techniques like X-rays to assess bone structure for conditions like Haglund’s deformity or heel spurs. They may also use ultrasound and MRI to evaluate soft tissue masses like cysts and fibromas. Obtaining an accurate diagnosis is necessary for determining the correct course of action, which may involve simple modifications, physical therapy, or targeted medical interventions. Never attempt to self-diagnose or treat a lump that exhibits concerning symptoms.