Numbness: Causes and When It Is an Emergency

What numbness feels like

Numbness can feel like reduced sensation, as if wearing a glove, a "dead" or wooden feeling, or complete loss of feeling. It often comes with paresthesia: tingling, prickling, buzzing or burning. Some people notice it only when they cannot feel temperature or drop things.

Sudden numbness: when it is an emergency

A stroke interrupts blood flow to part of the brain. Use BE FAST:

• Balance: sudden loss of balance
• Eyes: sudden vision loss or double vision
• Face: one side drooping or numb
• Arm: weakness or numbness in one arm
• Speech: slurred or strange speech
• Time: call 911 or your local emergency number immediately

Even symptoms that go away in minutes may be a transient ischemic attack (TIA), a warning stroke, and need same-day assessment. See stroke.

Common causes by body part

Fingers and hands

• Carpal tunnel syndrome: compression of the median nerve at the wrist. Numbness and tingling in the thumb, index, middle and half the ring finger, worse at night and when gripping. Shaking the hand often helps.
• Ulnar nerve compression: at the elbow (cubital tunnel). Numbness in the ring and little fingers, worse with the elbow bent.
• Pinched nerve in the neck: cervical radiculopathy causes neck pain and numbness running down the arm into specific fingers.
• Raynaud's phenomenon: fingers turn white and numb in the cold, then recover.

Arms

Numbness in one arm is often from a pinched nerve in the neck or sleeping on the arm. Arm numbness with chest pain, breathlessness or sweating may be a heart attack. Sudden numbness with weakness may be a stroke.

Feet and legs

• Peripheral neuropathy: numbness, tingling and burning in both feet, spreading up the legs in a "stocking" pattern. Diabetes is the most common cause; alcohol, B12 deficiency, chemotherapy, kidney disease and hypothyroidism are others.
• Sciatica: a pinched nerve in the lower back causing numbness down the back of the leg into the foot.
• Meralgia paresthetica: burning numbness on the outer thigh from a squeezed nerve.
• Peroneal nerve compression: numbness on the top of the foot and foot drop after crossing the legs or a tight cast.
• Morton's neuroma: numbness between the toes.

Face

• Stroke (sudden, with other signs)
• Bell's palsy, which mainly causes weakness rather than numbness
• Trigeminal nerve problems, dental procedures and shingles
• Migraine aura, which can cause tingling spreading over the face and hand over minutes

Other causes of numbness

• Vitamin B12 deficiency: numbness in the hands and feet, poor balance, fatigue and anemia. More common in older adults, vegans, people taking metformin or acid-suppressing medicines, and after stomach surgery.
• Multiple sclerosis: patches of numbness that come and go over days to weeks, often with vision problems, fatigue and balance issues.
• Anxiety and overbreathing: tingling in the lips and fingers.
• Low calcium: tingling around the mouth and fingers, with muscle cramps.
• Spinal cord compression: numbness below a certain level with weakness and bladder changes.
• Shingles: numbness or burning in a band before or after the rash.
• Medicines and toxins: chemotherapy, some HIV medicines, heavy metals.

How doctors find the cause

The exact pattern of numbness is the most useful clue: one nerve, one nerve root, both feet evenly, or one side of the body. A clinician will ask how fast it started, what makes it better or worse, and about diabetes, alcohol, diet, medicines and other symptoms.

Tests may include:

• blood tests: glucose and HbA1c, vitamin B12, thyroid function, kidney and liver function, blood count
• nerve conduction studies and EMG: to measure nerve function
• MRI of the brain or spine
• CT scan urgently for suspected stroke

Treatment

Treatment depends on the cause:

• Nerve compression: avoid the triggering position, use night splints for carpal tunnel, take breaks from repetitive tasks; steroid injection or surgery if severe.
• Pinched nerve in the neck or back: physical therapy, pain relief, and occasionally surgery.
• Diabetes: tight blood sugar control to slow nerve damage, and daily foot checks, because numb feet are easily injured.
• B12 deficiency: B12 injections or high-dose tablets.
• Stroke: emergency clot-busting or clot-removal treatment, which works best within hours.
• Nerve pain: medicines such as duloxetine, amitriptyline, gabapentin or pregabalin.

Protecting numb skin

Check numb feet daily for cuts or blisters, test bath water with your elbow, wear well-fitting shoes, and avoid heating pads on numb areas.

Frequently asked questions

What causes numbness in the fingers?

The most common cause is carpal tunnel syndrome, which numbs the thumb, index and middle fingers. Numbness of the ring and little fingers points to the ulnar nerve at the elbow. A pinched nerve in the neck, Raynaud's phenomenon, diabetes and vitamin B12 deficiency are other causes.

When should I worry about numbness?

Call 911 for sudden numbness on one side of the body, especially with weakness, facial drooping, slurred speech or vision loss. Seek urgent care for numbness in the groin area with bladder problems, or numbness spreading up both legs. See a doctor for numbness lasting more than a few days.

Can anxiety cause numbness?

Yes. Anxiety and panic attacks can cause tingling or numbness, usually in the lips, hands and fingers, often from rapid breathing. It comes and goes with anxiety and affects both sides. One-sided, persistent or sudden numbness should not be blamed on anxiety without medical assessment.

What deficiency causes numbness in the hands and feet?

Vitamin B12 deficiency is the most common nutritional cause. Low copper, vitamin B6 (and too much B6), and folate can also affect nerves. A blood test can confirm deficiency, and treatment can stop or reverse nerve damage if started early.

Why does my arm go numb at night?

Lying on your arm or sleeping with bent elbows or wrists compresses nerves, causing temporary numbness. Frequent night-time hand numbness is a classic sign of carpal tunnel syndrome. A wrist splint at night often helps. Persistent numbness during the day should be checked.