The sensation of “pins and needles” in the feet, medically termed paresthesia, is a common experience that most individuals encounter at some point. This feeling involves a temporary loss of sensation, tingling, or a prickling sensation. It occurs when the communication between nerves and the brain is briefly disrupted, leading to these unusual but often harmless feelings. While frequently temporary and benign, feet going numb can also indicate various underlying conditions, ranging from minor issues to more significant health concerns.
Everyday Reasons for Numbness
Feet frequently go numb due to temporary pressure on nerves or blood vessels, which often occurs from maintaining certain body positions for extended periods. When pressure is applied to a nerve, it can temporarily interrupt the transmission of signals between the nerve and the brain. This interruption can lead to a transient sensation of numbness or tingling. For example, sitting with legs crossed or sleeping in an awkward position can compress nerves in the leg or foot, leading to this effect.
The pressure can also restrict blood flow to the area, further disrupting nerve function. Once the pressure is relieved, blood flow resumes and nerve signals begin to transmit normally again, causing the “pins and needles” sensation. This type of numbness is short-lived and resolves quickly by changing position or moving the affected foot. Wearing tight shoes can similarly compress nerves and blood vessels, leading to temporary numbness in the toes or foot.
When Nerves Are Involved
Beyond temporary pressure, numbness in the feet can stem from more direct and persistent nerve issues. Localized nerve compression, often called a “pinched nerve,” can cause prolonged or frequent numbness. This occurs when a nerve is compressed or irritated by surrounding tissues like bone, cartilage, muscle, or tendons. For instance, a pinched nerve in the lower back, often due to a herniated disc, can radiate pain and numbness down the leg into the foot, a condition known as sciatica.
Another example is tarsal tunnel syndrome, where the tibial nerve, running along the inside of the ankle, becomes compressed. This compression can lead to numbness, tingling, and pain in the ankle, heel, and sole of the foot. Unlike temporary numbness from awkward positions, these localized nerve issues cause symptoms because the nerve is continuously irritated or damaged, leading to persistent sensations, muscle weakness, or pain. The consistent pressure or entrapment directly interferes with the nerve’s ability to transmit signals effectively.
Health Issues That Can Cause Numbness
Persistent or recurring foot numbness can also be a symptom of serious medical conditions affecting nerve health. Diabetes is a common cause, as high blood sugar levels can damage nerves over time, leading to diabetic neuropathy, which often begins with numbness and tingling in the feet and hands. Certain vitamin deficiencies, particularly a lack of vitamin B12, can also impair nerve function and result in numbness.
Other systemic conditions, like multiple sclerosis, can cause numbness due to damage to the protective covering of nerve fibers in the central nervous system. Chronic alcohol abuse can lead to alcoholic neuropathy, resulting from direct toxic effects and nutritional deficiencies. Some medications, including certain chemotherapy drugs, can cause peripheral neuropathy, leading to numbness in the extremities. These conditions require a medical diagnosis and management to address the cause of the nerve damage.
When to Talk to a Doctor
Consult a doctor if foot numbness is sudden, severe, or spreads rapidly. Seeking medical attention is important if the numbness is persistent, occurring frequently without an obvious cause, or accompanied by other concerning symptoms. These additional symptoms might include muscle weakness, difficulty walking, or changes in sensation like extreme sensitivity or loss of temperature perception. Numbness that develops after a recent injury or trauma to the back, leg, or foot should also prompt a medical evaluation. A healthcare professional can diagnose the cause of the numbness and recommend treatment or management.