The sudden onset of numbness, or paresthesia, in the right heel is often described as a pins-and-needles sensation or a complete loss of feeling. This localized symptom results from the irritation or compression of a nerve supplying sensation to the area. Causes range from simple, temporary issues like external pressure to complex underlying conditions involving the spine or metabolic health. Understanding the potential sources of this nerve irritation is the first step toward finding relief.
Localized Nerve Entrapment in the Foot
Numbness confined precisely to the heel often points toward a nerve compressed within the foot or ankle itself. Two specific nerve entrapment syndromes are the most likely localized causes.
Tarsal Tunnel Syndrome (TTS)
Tarsal Tunnel Syndrome (TTS) involves the posterior tibial nerve, which travels through the tarsal tunnel, a narrow space on the inside of the ankle near the heel bone. The tunnel also contains arteries and tendons, and any swelling or internal lesion (such as a cyst, bone spur, or enlarged vein) can press on the nerve. Compression of the posterior tibial nerve commonly results in burning, tingling, or numbness affecting the heel and the sole of the foot. Poor foot mechanics, like flat feet, can contribute to TTS by increasing strain and compression on the nerve.
Baxter’s Nerve Entrapment
Baxter’s nerve entrapment, also known as inferior calcaneal nerve entrapment, is another specific cause of heel numbness. Baxter’s nerve is a small branch of the lateral plantar nerve that runs across the bottom of the foot near the heel bone. Compression, often occurring between the abductor hallucis muscle and the quadratus plantae muscle, causes pain and numbness directly in the heel. This entrapment is sometimes overlooked because its symptoms can mimic those of plantar fasciitis, but it explains localized numbness on the bottom or outer edge of the heel.
Systemic Conditions and Spinal Causes
The source of heel numbness may originate far from the foot, traveling down the leg from the spine or as a manifestation of a broader systemic disease. When a nerve root is compressed in the lower back, radiculopathy (commonly known as sciatica) can cause referred pain and numbness in the extremities.
S1 Radiculopathy
Compression of the S1 (first sacral) nerve root, often due to a herniated disc or spinal stenosis, can send symptoms down the back of the leg and into the foot. S1 radiculopathy results in numbness or tingling along the back of the calf and into the outside or bottom of the foot, directly affecting the heel. This spinal cause usually affects only one side of the body, aligning with isolated right heel numbness.
Peripheral Neuropathy
Systemic conditions like peripheral neuropathy involve nerve damage caused by internal metabolic issues rather than physical compression. Uncontrolled diabetes is the most common cause, where chronically high blood sugar levels damage the small sensory nerve fibers. This neuropathy typically begins in a “stocking-and-glove” pattern, first affecting the toes and feet symmetrically, but it can be noticed initially in one area like the heel. Other metabolic or inflammatory diseases, such as hypothyroidism or certain autoimmune disorders, can also lead to peripheral neuropathy manifesting as heel numbness.
Mechanical Pressure and Footwear Factors
Sustained Pressure
The simplest explanations for temporary heel numbness involve external mechanical forces that briefly compress a nerve or restrict circulation. Sustained pressure on a nerve, such as sitting cross-legged for an extended period, is a frequent cause of temporary numbness (paresthesia) where the foot “falls asleep.” This can compress the peroneal nerve near the knee, resulting in temporary tingling and numbness down the leg and foot.
Footwear and Trauma
Ill-fitting or excessively tight footwear is another common culprit, creating localized pressure on nerves and blood vessels. Shoes with a constrictive heel counter can directly press on nerves supplying the heel, causing a temporary loss of sensation that subsides quickly once the footwear is removed. Acute trauma, such as an ankle sprain, can also lead to temporary heel numbness due to swelling and inflammation. The resulting fluid buildup can compress a nearby nerve, which usually resolves as the swelling decreases.
Recognizing When to Consult a Doctor
When to Seek Non-Urgent Care
While temporary numbness often resolves on its own, certain symptoms warrant a medical evaluation to rule out a more serious underlying issue. Schedule an appointment if the numbness persists for several weeks without an obvious cause, such as a change in footwear or prolonged awkward positioning. Persistent numbness that does not improve with conservative measures, like rest and ice, requires a thorough examination.
Immediate Medical Attention
Specific “red flag” symptoms signal a need for immediate medical attention, particularly if the numbness is accompanied by a sudden loss of motor function. Seek urgent care if the numbness is rapidly spreading up your leg or if you experience muscle weakness that makes walking difficult. Numbness combined with a change in bladder or bowel control is a serious sign of potential severe spinal nerve compression and requires immediate evaluation. Individuals with diabetes should report any new or worsening numbness immediately, as it may indicate progressive nerve damage.