Tingling and numbness are abnormal sensations that can occur anywhere in the body but is most commonly felt in the hands and feet.

Numbness or hypoesthesia is a broad term ranging from the harmless numbness you get when your fingers are too cold over a lack of sensation, a loss of sensibility, a lack of feeling, deadness, insensibility, anesthetized, asleep, indifferent or dead feeling.

Tingling is an abnormal sensation of pins and needles, like ants running which are named paraesthesia as well.

Causes

• Sitting or standing in the same position for a long time
• Pressure on a peripheral nerve as e.g. Carpal tunnel Syndrome
• Lack of Vitamin B12 or other vitamins (E, B1, B6, niacin)
• Over dosage of Vitamin B6
• Low thyroid hormones
• Iron deficiency
• Diabetes
• Abnormal levels of calcium, potassium or sodium
• Shingles or herpes zoster infection
• Side effect of medication
• Toxins (heavy metals such as lead, arsenic, mercury and thallium)
• Multiple Sclerosis
• Stroke / Transient ischemic attack (TIA)
• Pressure on the nerves of the spine, such as from a herniated disk
• Lack of blood supply to a limb, such as from hardening of the arteries or vessel inflammation
• Raynaud phenomenon (narrowing of the blood vessels, usually in the hands and feet)

Diagnosis

We starts diagnosing by taking an extensive medical history addressing your symptoms, the trigger factors, the duration and the frequency, work environment, social habits, toxic exposure, risk of infectious diseases and family history of neurological disease. Check of vital signs such as blood pressure and pulse, followed by a proper physical examination focusing on sensibility, general and specific motor power testing, tabbing the muscle stretch reflexes should give first differential diagnosis. Additional tests such as laboratory tests of blood and cerebro spinal fluid, Electromyography (EMG), Nerve Conduction Studies (NCS) and imaging of brain are sometimes necessary for confirmation of diagnosis.