The sensation of numbness or tingling in the heel is medically termed paresthesia. This symptom indicates that a nerve responsible for sensation in that area is irritated, compressed, or damaged. Understanding the source of this nerve irritation is the first step toward finding relief. Causes can range from mechanical pressure within the foot to systemic conditions affecting nerves throughout the body.
Localized Nerve Entrapment in the Ankle and Foot
Numbness originating in the heel often involves the compression of specific nerves as they pass through the foot and ankle structure. These conditions are typically unilateral, affecting only one foot, and are often related to foot mechanics, injury, or inflammation. Two common localized entrapment syndromes are Tarsal Tunnel Syndrome and Baxter’s Nerve Entrapment.
Tarsal Tunnel Syndrome (TTS) involves the posterior tibial nerve as it travels through a narrow passageway on the inside of the ankle, beneath the flexor retinaculum ligament. Swelling, a bone spur, or structural changes within this tunnel can increase pressure on the nerve. Compression causes numbness, burning pain, and tingling that affects the heel, the arch, and sometimes extends into the toes. Symptoms often worsen with prolonged standing or activity.
Baxter’s Nerve Entrapment involves the first branch of the lateral plantar nerve, often called Baxter’s nerve. This small nerve runs underneath the arch and is compressed as it passes between the abductor hallucis and the quadratus plantae muscles. Compression is frequently exacerbated by structural issues like flat feet or swelling associated with long-standing heel conditions. Symptoms are concentrated deep in the inner and bottom parts of the heel, leading to frequent misdiagnosis as plantar fasciitis.
Systemic Conditions and Referred Pain
Heel numbness can result from a problem occurring higher up the leg or a condition affecting the entire nervous system. When a nerve is compressed in the back, the resulting sensation is known as referred pain. Systemic diseases, in contrast, cause direct damage to the nerve fibers themselves.
Referred pain from the lumbar spine is a common source of sensation changes, often described as sciatica. Sciatica occurs when a herniated disc, bone spur, or spinal stenosis puts pressure on the nerve roots in the lower back. Because the sciatic nerve branches supply the heel, this compression causes numbness, pain, or tingling that radiates from the lower back, down the leg, and into the foot. Sciatica is generally unilateral and often presents with accompanying lower back or hip pain.
Peripheral neuropathy, particularly related to diabetes, is a systemic cause where high blood sugar levels damage nerve fibers over time. This damage causes a loss of sensation, tingling, or burning, typically affecting both feet symmetrically in a “stocking-like” pattern. While starting in the toes, it can involve the heel. Other conditions, such as vitamin deficiencies, autoimmune disorders, or long-term alcohol use, can also result in peripheral neuropathy affecting the feet.
Immediate Self-Care and Assessing Urgency
For intermittent, localized numbness not associated with trauma, self-care can provide relief by reducing pressure and inflammation. Resting the foot and avoiding aggravating activities, such as prolonged standing or high-impact exercise, is a primary step. Applying ice to the heel or ankle where compression is suspected can help reduce swelling that may be pressing on the nerve.
Changing footwear to shoes with a wider toe box and better arch support can alleviate pressure points that irritate nerves. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) may also help temporarily reduce localized inflammation and pain. If the numbness persists for more than a week, worsens, or begins to interfere with walking, a professional medical evaluation is warranted.
Certain symptoms require immediate medical attention to prevent permanent nerve damage or address a serious underlying condition. Seek emergency care if the numbness begins suddenly after a traumatic injury or is accompanied by acute muscle weakness in the leg or foot. Loss of bladder or bowel control alongside leg or foot numbness is a neurological emergency indicating severe spinal cord or nerve root compression. Numbness combined with signs of infection, such as fever, redness, or pus, also necessitates prompt medical evaluation.
Professional Diagnostic Steps and Medical Treatment
When numbness does not resolve with self-care, a healthcare professional will perform a thorough physical examination and medical history. The clinician tests reflexes, muscle strength, and sensation to determine the extent and pattern of sensory loss. Specific diagnostic tests are then used to confirm nerve involvement and identify any structural causes of compression.
Nerve Conduction Studies (NCS) and Electromyography (EMG) evaluate the function of peripheral nerves and muscles. NCS measures the speed and strength of electrical signals traveling through a nerve, confirming damage or entrapment and locating the compression point. EMG involves inserting fine needles into muscles to record electrical activity, determining if nerve damage affects muscle function.
Imaging studies like X-rays can rule out bone spurs or fractures. Magnetic Resonance Imaging (MRI) or ultrasound can visualize soft tissues to identify tumors, cysts, or inflammation pressing on a nerve.
Treatment pathways are tailored to the diagnosis, often beginning with conservative measures. These include custom orthotics to correct foot biomechanics or physical therapy to improve flexibility and strength. Corticosteroid injections may be used to reduce inflammation around the compressed nerve. For severe, chronic nerve entrapments that fail to respond to these methods, surgical decompression may be necessary to relieve pressure.