Paresthesia: What It Means and What Causes It

Paresthesia definition

The word comes from Greek para (abnormal) and aisthesis (sensation). Paresthesia of the skin is a sensation such as tingling, prickling, buzzing, crawling, burning or partial numbness that arises from the nerves rather than from a real stimulus. It is a symptom, not a diagnosis.

Doctors distinguish it from related terms:

Transient paresthesia is temporary, such as a foot that "falls asleep". Chronic paresthesia lasts weeks or longer and usually signals nerve damage or disease.

Why paresthesia happens

Sensory nerves carry signals from the skin to the spinal cord and brain. When a nerve is pressed, starved of blood, inflamed or damaged, it fires abnormally or fails to fire. The brain reads these misfiring signals as tingling or numbness in the area that nerve supplies. That is why the pattern of tingling helps locate the problem:

• One finger area or one side of the hand: a single compressed nerve (carpal tunnel, ulnar nerve at the elbow)
• A strip down the arm or leg: a pinched nerve root in the neck or lower back
• Both feet, then hands ("glove and stocking"): a generalized neuropathy, such as from diabetes
• One whole side of the body: the brain or spinal cord

Common causes of paresthesia

Pressure on a nerve

Sitting cross-legged, sleeping on an arm or leaning on an elbow temporarily squeezes a nerve. Sensation returns, often with a burst of pins and needles, within minutes of moving.

Nerve entrapment

• Carpal tunnel syndrome: tingling in the thumb, index and middle fingers, often waking you at night.
• Ulnar nerve compression: tingling in the ring and little fingers, worse with the elbow bent.
• Meralgia paresthetica: burning tingling on the outer thigh from a compressed thigh nerve, linked to tight belts and weight gain.
• Tarsal tunnel syndrome: tingling in the sole of the foot.

Pinched nerve roots in the spine

Cervical radiculopathy causes tingling running down the arm. Sciatica causes tingling down the back of the leg into the foot. Both often come with neck or back pain.

Diabetes and other neuropathies

Diabetic peripheral neuropathy is the most common cause of long-term paresthesia in both feet. Other causes of peripheral neuropathy include alcohol misuse, kidney failure, an underactive thyroid, chemotherapy, HIV and some inherited conditions.

Vitamin deficiencies

Low vitamin B12 is an important, treatable cause. It is more common in older adults, vegans, people taking metformin or acid-reducing medicines long term, and after weight-loss surgery. Low B1, B6 and copper can do the same. Too much vitamin B6 from supplements can also cause neuropathy.

Fast breathing and anxiety

Hyperventilation during anxiety or a panic attack lowers carbon dioxide in the blood, causing tingling in both hands and around the mouth. It eases as breathing slows.

Medicines and toxins

Some chemotherapy drugs, certain antibiotics, HIV medicines, heavy metals and solvents can damage nerves.

Serious causes

• Stroke or transient ischemic attack: sudden one-sided numbness or tingling, often with weakness or speech problems.
• Multiple sclerosis: episodes of tingling or numbness lasting days, sometimes with vision problems or an electric shock feeling when bending the neck.
• Guillain-Barré syndrome: rapidly rising tingling and weakness, often after an infection.
• Spinal cord compression: tingling in both legs, unsteadiness and bladder problems.
• Low calcium: tingling around the mouth and fingertips with muscle cramps.

How doctors find the cause

A doctor will ask where the paresthesia is, when it started, whether it comes and goes, and about weakness, pain, diabetes, alcohol, diet and medicines. They test sensation, strength, reflexes and balance. Common tests include:

• Blood tests: glucose and HbA1c, vitamin B12, thyroid function, kidney and liver function, full blood count.
• Nerve conduction studies and electromyography (EMG): measure how well nerves and muscles carry signals.
• MRI of the brain or spine: if a central cause or nerve root compression is suspected.

Paresthesia treatment

Treatment depends on the cause:

• Nerve compression: wrist splints at night, changing activities, physical therapy, steroid injections and, if needed, surgery to release the nerve.
• Diabetes: better blood sugar control slows nerve damage. Daily foot checks prevent unnoticed injuries.
• Vitamin B12 deficiency: B12 injections or high-dose tablets. Early treatment gives the best chance of full recovery.
• Alcohol-related neuropathy: stopping alcohol and taking thiamine.
• Painful paresthesia: prescription nerve pain medicines such as duloxetine, pregabalin, gabapentin or amitriptyline. Standard painkillers work poorly.
• Hyperventilation: slow breathing techniques and treatment of anxiety.

Frequently asked questions

What is paresthesia?

Paresthesia is an abnormal sensation in the skin, such as tingling, prickling, pins and needles or numbness, that happens without an outside cause. It comes from irritated, compressed or damaged nerves and can be brief or long-lasting.

What is the definition of paresthesia of the skin?

It is a sensorineural change in which the skin feels numb, tingly, prickly or as if insects are crawling on it, without any physical stimulus. It reflects abnormal firing of sensory nerves somewhere between the skin and the brain.

Is paresthesia serious?

Brief pins and needles from pressure are harmless. Chronic paresthesia needs assessment because it often signals nerve compression, diabetes or vitamin deficiency. Sudden one-sided tingling with weakness or speech problems can be a stroke and is an emergency.

Can anxiety cause paresthesia?

Yes. Anxiety and panic can trigger fast breathing that causes tingling in the hands, feet and around the mouth. It settles as breathing returns to normal. New or one-sided tingling should still be checked by a doctor.

Can paresthesia be cured?

Often, yes, if the cause is treated early. Tingling from nerve compression, B12 deficiency or medicines frequently improves or goes away. Long-standing nerve damage from diabetes may be permanent, but treatment can slow progression and ease symptoms.

What vitamin deficiency causes paresthesia?

Vitamin B12 deficiency is the most common. Low vitamin B1 (thiamine), B6 and copper can also cause it. Paradoxically, taking too much vitamin B6 from supplements over a long time can cause tingling in the hands and feet.