Numbness and Tingling in Hands and Feet: Causes and Next Steps

What causes numbness and tingling in the extremities?

Numbness and tingling (the medical term is paresthesia) reflect disruption of sensory nerve signals — either at the nerve itself, where it exits the spine, or in the peripheral nervous system. The sensation is the nerve's way of signaling that something is interfering with its normal function.

The causes range from entirely benign (a compressed nerve from sitting on your foot) to conditions that warrant treatment. Identifying which category applies depends on the pattern, duration, and associated symptoms.

Common causes: nerve compression

Carpal tunnel syndrome — compression of the median nerve at the wrist — is one of the most common causes of hand numbness and tingling. It classically affects the thumb, index, and middle fingers, and is often worse at night or with prolonged gripping. Risk factors include repetitive hand use, pregnancy, and hypothyroidism.

Cubital tunnel syndrome — ulnar nerve compression at the elbow — causes numbness and tingling in the ring and little fingers, often worsened by bending the elbow for extended periods.

Cervical radiculopathy — a pinched nerve root in the neck — can radiate numbness down the arm and into the fingers in a pattern that follows the nerve root's distribution.

Lumbar radiculopathy — a pinched nerve in the lower back — can cause numbness or tingling that runs down the leg and into the foot (sciatica is a related pattern).

Prolonged pressure — sitting cross-legged or sleeping in an awkward position temporarily compresses a nerve; this resolves quickly once pressure is relieved and does not indicate disease.

Common causes: systemic conditions

Diabetes and prediabetes — high blood glucose damages small nerve fibers over time, producing a symmetrical, stocking-and-glove pattern of numbness and tingling that starts in the feet and, in advanced cases, progresses to the hands. This is peripheral neuropathy, and it is one of the most important reasons to screen for diabetes when these symptoms appear 1Ref 1American Diabetes Association Professional Practice Committee (2024).Standards of Care in Diabetes—2024.Diabetic peripheral neuropathy as a common complication of high blood glucose; screening recommendation.

Vitamin B12 deficiency — B12 is essential for the myelin sheath that insulates nerve fibers. Deficiency causes tingling, numbness, and imbalance, often in a symmetric pattern beginning in the feet. Risk groups include vegetarians and vegans, older adults, people on metformin, and those with certain GI conditions 2Ref 2Obeid R, Andrès E, Česka R, et al. (2024).Diagnosis, Treatment and Long-Term Management of Vitamin B12 Deficiency in Adults: A Delphi Expert Consensus.B12 deficiency as a cause of symmetric peripheral neuropathy; at-risk groups.

Hypothyroidism — an underactive thyroid can cause peripheral neuropathy, carpal tunnel syndrome, and generalized tingling. It is a treatable and often overlooked cause 3Ref 3Jonklaas J, Bianco AC, Bauer AJ, et al. (2014).Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement.Hypothyroidism as a cause of peripheral neuropathy and carpal tunnel syndrome; treatable with hormone replacement.

Alcohol overuse — chronic heavy alcohol use causes direct nerve toxicity and also depletes B vitamins, both contributing to peripheral neuropathy.

Autoimmune conditions — multiple sclerosis, lupus, and other autoimmune disorders can affect the nervous system and cause tingling, particularly if the pattern is asymmetric or accompanied by other neurological symptoms.

Anxiety and hyperventilation — rapid, shallow breathing lowers carbon dioxide levels and causes tingling around the mouth and in the extremities. This resolves when breathing normalizes.

What does the pattern of symptoms tell you?

The distribution of tingling is one of the most useful clues:

• Both feet symmetrically, starting at the toes — suggests peripheral neuropathy (diabetes, B12, alcohol)
• One hand's specific fingers — suggests carpal tunnel or cubital tunnel (nerve compression)
• Down one arm or one leg — suggests nerve root compression from the spine
• One side of the body — suggests a central cause such as stroke or MS and warrants prompt evaluation
• Around the mouth and fingertips simultaneously — suggests anxiety/hyperventilation
• Comes and goes with position — suggests compression that resolves when pressure is relieved

What tests will a clinician order?

A primary care clinician will take a history, perform a neurological examination, and order targeted blood tests. These commonly include: - Fasting blood glucose and HbA1c (for diabetes) - Vitamin B12 level - Thyroid function (TSH) - Complete blood count (for anemia) - Metabolic panel - Possibly B6 levels (both deficiency and excess can cause neuropathy)

If nerve compression is suspected, nerve conduction studies or electromyography (EMG) may be ordered or arranged through a neurology referral. If a central cause is suspected, imaging (MRI) is appropriate.

When should I see a clinician?

See a Gale primary care clinician if: - Tingling or numbness has persisted for more than a few weeks - It is progressing — affecting more of your feet, hands, or legs over time - It is accompanied by weakness, balance problems, or coordination difficulties - You have diabetes or risk factors for it - You follow a vegetarian or vegan diet without regular B12 supplementation

Early evaluation is worthwhile because several of the most common causes — diabetes, B12 deficiency, hypothyroidism — are treatable and the nerve damage is at least partially reversible when caught early 4Ref 4National Institute of Neurological Disorders and Stroke (2023).Peripheral Neuropathy.Overview of peripheral neuropathy causes and reversibility when underlying causes are treated early.