What causes leg numbness?

Leg numbness can be a symptom of a wide variety of diseases, disorders or conditions that either restrict blood flow or cause injury to the nerves.

Temporary leg numbness can occur after prolonged pressure on a nerve or nerves, such as after sitting cross legged or bicycling long distance.

Leg numbness can occur with moderate to serious orthopedic conditions that can lead to spinal or peripheral nerve damage. More serious conditions include multiple sclerosis.

Whether the numbness occurs in one or both legs can help your doctor diagnose the underlying cause. For example, numbness in one leg can indicate a compressed nerve in the lower spine, whereas numbness in both legs (and other extremities) may be a sign of a more systemic disease (in which multiple body parts are affected) such as multiple sclerosis or pernicious anemia.

In some cases, leg numbness can be a sign of a serious or life-threatening disease or condition that should be evaluated as soon as possible or in an emergency medical setting.

Circulatory causes of leg numbness

Leg numbness can be caused by lack of blood flow to an area due to such conditions as:

  • Arteriovenous malformation (tangled knot of arteries and veins)

  • Buerger’s disease (acute inflammation and clotting of arteries and veins)

  • Deep vein thrombosis (blood clot in the leg that can break loose from the leg causing a pulmonary embolism in the lung, a heart attack, or even stroke)

  • Frostbite or extremely cold temperatures

  • Peripheral artery disease (PAD, also called peripheral vascular disease, or PVD, which is a narrowing of arteries due to a buildup of fat and cholesterol on the artery walls, which limits blood flow to the extremities)

Orthopedic causes of leg numbness

Leg numbness may also occur because of moderate to serious orthopedic conditions that injure of damage the nerves including:

  • Back injury

  • Bone fractures or a cast that is too tight

  • Degenerative disk disease

  • Herniated disk

  • Nerve entrapment or nerve pressure, such as from sitting too long

  • Osteoporosis

Neurological causes of leg numbness

Leg numbness caused by nerve compression or damage may be due to such conditions as:

  • Alcoholism

  • Back or neck injury

  • Diabetic neuropathy (nerve damage due to high blood sugar levels associated with diabetes)

  • Heavy metal poisoning such as lead poisoning

  • Hypothyroidism (underactive thyroid)

  • Multiple sclerosis (disease that affects the brain and spinal cord)

  • Peripheral neuropathy (disorder of the peripheral nerves)

  • Spinal cord injury or tumor

  • Stroke

  • Systemic lupus erythematosus (a disorder in which the body attacks its own healthy cells and tissues)

  • Transverse myelitis (neurological disorder causing inflammation of the spinal cord)

  • Vitamin B12 deficiency (as in pernicious anemia)

What are the potential complications of leg numbness?

Because leg numbness can be due to serious diseases, failure to seek treatment can result in complications and permanent damage. It is important to contact your health care provider when you experience any kind of persistent numbness or other unusual symptoms. Once the underlying cause is diagnosed, it is important to follow the treatment plan outlined by your health care provider to reduce your risk of potential complications related to leg numbness, such as:

  • Amputation

  • Disability

  • Inability to walk

  • Organ failure

  • Paralysis

  • Permanent loss of sensation

  • Permanent pain

  • Poor quality of life

INTRODUCTION

What is leg numbness?

Leg numbness is an abnormal condition in which you feel a loss of sensation in the legs. You can have numbness of one (unilateral) or both (bilateral leg numbness) legs. Numbness in the legs may also extend to your toes.

... Read more about leg numbnessintroduction

SYMPTOMS

What other symptoms might occur with leg numbness?

Leg numbness may occur with other symptoms or a combination of symptoms. For example, if your legs are numb because of a compressed nerve in the lumbar spine (lower back), you may also experience pain in the legs and back. Leg numbness due to multiple sclerosis can be associated with tingling and extreme itchiness. Any symptoms occurring with leg numbness can help your doctor make a diagnosis.<... Read more about leg numbnesssymptoms

Medical Reviewer: Cynthia Haines, MD Last Annual Review Date: Aug 5, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

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