Numbness and tingling

Causes
There are many possible causes of numbness and tingling:

• Sitting or standing in the same position for a long time
• Injuring a nerve (a neck injury may cause you to feel numbness anywhere along your arm or hand, while a low back injury can cause numbness or tingling down the back of your leg)
• Pressure on the nerves of the spine, such as from a herniated disk
• Pressure on peripheral nerves from enlarged blood vessels, tumors, scar tissue, or infection
• Shingles or herpes zoster infection
• Lack of blood supply to an area (for example, from atherosclerosis or frostbite)
• Other medical conditions, including:
• Carpal tunnel syndrome (pressure on a nerve at the wrist)
• Diabetes
• Migraines
• Multiple sclerosis
• Seizures
• Stroke
• Transient ischemic attack (TIA), sometimes called a "mini-stroke"
• Underactive thyroid
• Raynaud's phenomenon
• Abnormal levels of calcium, potassium, or sodium in your body
• A lack of vitamin B12 or other vitamin
• Use of certain medications
• Nerve damage due to lead, alcohol, or tobacco
• Radiation therapy
• Animal bites
• Insect, tick, mite, and spider bites
• Seafood toxins

Home Care
Your doctor should find and treat the cause of your numbness or tingling. Treating the condition may make the symptoms go away or stop them from getting worse. For example, if you have carpal tunnel syndrome or low back pain, your doctor may recommend certain exercises.

If you have diabetes, your doctor will discuss ways to control your blood sugar levels.

Low levels of vitamins will be treated with vitamin supplements.

Medications that cause numbness or tingling may need to be switched or changed. Do not change or stop taking any of your medicines or take large doses of any vitamins or supplements until you have talked with your doctor.

Because numbness can cause a decrease in feeling, you may be more likely to accidentally injure a numb hand or foot. Take care to protect the area from cuts, bumps, bruises, burns, or other injuries.

When to Contact a Medical Professional
Go to a hospital or call your local emergency number (such as 911) if:

• You have weakness or are unable to move (paralysis), along with numbness or tingling
• Numbness or tingling occur just after a head, neck, or back injury
• You cannot control the movement of an arm or a leg or you have lost bladder or bowel control
• You are confused or have lost consciousness, even briefly
• You have slurred speech, a change in vision, difficulty walking, or weakness

Call your doctor if:

• Numbness or tingling has no obvious cause (like a hand or foot "falling asleep")
• You have pain in your neck, forearm, or fingers
• You are urinating more often
• Numbness or tingling is in your legs and gets worse when you walk
• You have a rash
• You have dizziness, muscle spasm, or other unusual symptoms

What to expect at your health care provider's office
Your health care provider will take a medical history and perform a physical examination, carefully checking your nervous system.

Medical history questions may include:

• What part or parts of your body have numbness or tingling? The trunk? Your legs or feet? Your arms, hands, or fingers?
• Which side of your body is involved?
• Which area of that body part? For example, is your inner thigh, calf, or foot affected? Your palm, fingers, thumb, wrist, or forearm?
• Does the numbness or tingling affect your face? Around your eyes? Your cheeks? Around your mouth? Is one or both sides of your face involved?
• Does the part of your body with numbness or tingling change colors? Does it feel cold or warm?
• Do you have other abnormal sensations?
• Do you ignore everything on the affected side?
• How long have you had the numbness or tingling?
• When did it start?
• Does anything make it worse, such as exercise or standing for long periods of time?
• Do you have any other symptoms?

Your doctor may also ask you questions to determine your risk for stroke, thyroid disease, or diabetes, as well as questions about your work habits and medications.

Blood tests may include:

• Complete blood count ( CBC)
• Electrolyte level (measurement of body chemicals and minerals)
• Thyroid function tests
• Measurement of vitamin levels
• Heavy metal or toxicology screening

Imaging tests may include:

• Angiogram (a test that uses x-rays and a special dye to see inside the blood vessels)
• CT angiogram
• CT scan of the head
• CT scan of the spine
• MRI of the head
• MRI of the spine
• Ultrasound of neck vessels to determine your risk for TIA or stroke
• Vascular ultrasound
• X-ray of the affected area

Other tests that may be done include:

• Electromyography and nerve conduction studies to measure how your muscles respond to nerve stimulation
• Lumbar puncture (spinal tap) to rule out central nervous system disorders
• Cold stimulation test may be done to check for Raynaud's phenomenon

Alternative Names
Sensory loss; Paresthesias; Tingling and numbness; Loss of sensation

References
Creager MA, Libby P. Peripheral arterial disease. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 8th ed. Saunders; 2007:chap 57.

Rowland LP. Diagnosis of pain and paresthesias. In: Rowland LP, ed. Merritt's Neurology . 11th ed. Baltimore, Md: Lippincott Williams & Wilkins; 2005:chap 5.

Mahoney BD. Spinal cord injuries. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 30.

Farmer BM, Dowsett RB, Nelson LS. Seafood Toxins. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 343.

Suchard JR. Scorpion envenomation. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 357.

Playe SJ. Mammalian bites and associated infections. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 361.

Burns MJ. Insect, tick, and mite bites and infestations. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 360.

Update Date: 4/3/2011
Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.