Numbness

What is numbness?

Numbness is a loss of feeling or sensation in an area of your body. It can be complete (no feeling at all) or partial (less feeling than usual). It usually affects your hands, fingers, feet, arms or legs, but it can occur in any part of your body. Numbness is usually a sign of a problem with your nerves, although it’s a common symptom of many different medical conditions.

Most cases of numbness aren’t serious. In more severe cases, it can cause complications related to not feeling pain (for example, causing burns if you’re unable to feel the pain from high heat) or being unaware of what’s happening to parts of your body (for example, falling if you’re unable to feel the position of your feet). You may not be able to tell hot from cold or sense vibrations. Numbness can also cause issues with balance and coordination. It can affect your ability to drive or walk.

Along with numbness, you may also have tingling or a pins-and-needles feeling in your body. You may also experience weakness and paralysis.

What are the most common causes of numbness?

Numbness has many possible causes. A problem with one or more nerves usually causes the symptom. When a nerve is damaged, it interferes with your body’s ability to feel normal sensations.

Some cases of numbness involve abnormal pressure on the nerves in and around your spine. Conditions that may cause this numbness include:

• Collapsed backbone due to osteoporosis.
• Peripheral neuropathy.
• Nerve compression syndromes.
• Neuropathic pain.
• Ruptured or herniated disk.
• Pinched nerve due to arthritis or bone spurs.
• Injury to your spinal cord, brain or nerves.

Other medical conditions that may cause numbness include:

• Carpal tunnel syndrome.
• Diabetes.
• Infections such as shingles, HIV or Lyme disease.
• Kidney disease.
• Multiple sclerosis (MS).
• Stroke.
• Arthritis.
• Tumor.
• Spread of cancer to your spine.
• Migraines.
• Seizures.
• Underactive thyroid (hypothyroidism).
• Raynaud’s syndrome.

Other conditions that may cause numbness include:

• Standing or sitting in the same position for a long time.
• Medications or drug use.
• Vitamin B deficiency.
• Animal and insect bites.
• Exposure to poisons or toxins.
• Lack of blood supply.
• Abnormal levels of potassium, calcium or sodium in your body.
• Nerve damage due to alcohol or tobacco use.
• Chemotherapy drugs.
• Radiation therapy.

How is numbness diagnosed?

Healthcare providers diagnose numbness based on your symptoms, medical history and a physical exam (testing touch, temperature, reflexes and muscle function). Your provider will ask you about the affected body part(s) and ask you to describe the numbness. Other questions will include:

• When the numbness started.
• How quickly the numbness began.
• The events or activities you were engaged in around the time the numbness began.
• If you have any other symptoms.

Answers to these questions can help your provider determine the cause of the numbness.

What tests will be done to find out the cause of numbness?

Tests to identify the disorder causing numbness include blood tests, imaging tests and other studies.

Blood tests

A healthcare provider will take a blood sample to look for signs of conditions, including diabetes, kidney disorders and vitamin deficiencies. Blood tests may include:

• Complete blood count (CBC).
• Electrolyte panel.
• Liver function tests.
• Thyroid function tests.
• Measurement of vitamin levels.
• Toxicology screening.
• Sedimentation rate.
• C-reactive protein.

Imaging tests

Imaging tests allow healthcare providers to look for issues affecting your nerves and spinal cord, such as a herniated disk or a tumor. They may use imaging to look at your brain for signs of stroke, multiple sclerosis, tumors and other brain disorders. Imaging tests may include:

• X-rays.
• CT scans (computed tomography scans) of your head and spine.
• MRI scans (magnetic resonance imaging) of your head and spine.
• Angiogram.
• Ultrasound of neck blood vessels.
• Vascular ultrasound.

Other studies

Other studies may include the following:

• Nerve conduction studies: In this test, a healthcare provider places electrodes over the nerve(s) to be studied and the muscle supplied by the nerve. A brief electric pulse is sent to the nerve. The test determines if the nerve transmitted the signal properly and at normal speed. If not, this is a sign of nerve injury or damage.
• Electromyography (EMG): In this test, a provider inserts a small needle in a muscle. A machine records electrical activity when your muscle is at rest and contracted. This test, often performed with nerve conduction studies, helps detect damage to nerves and muscles.
• Spinal tap (lumbar puncture): Providers may use this test to rule out central nervous system disorders.
• Genetic testing: Your healthcare provider may recommend genetic testing to check for nerve problems that run in your family.

How is numbness treated?

Treatment for numbness varies according to the cause. The goal of treatment is to correct the condition causing the numbness. Your healthcare provider will determine the best treatment for you based on the underlying condition and the nerves involved. Some common treatments for numbness include:

• Nerve pain medications.
• Regulating blood sugar in people with diabetes.
• Vitamin supplements to treat vitamin deficiencies.
• Physical therapy exercises to strengthen your spine or help ease movement.
• Surgery to remove a tumor or repair a problem in your spine.

When should I call my healthcare provider?

Because the causes of numbness vary greatly, some cases require more urgent medical care than others. Seek emergency medical attention if you have numbness along with:

• Confusion.
• Inability to control bladder or bowel movements.
• Loss of consciousness.
• Difficulty breathing.
• Loss of sensation in your face or trunk of your body.
• Paralysis.
• Speech or vision changes.
• Rapid or sudden weakness.

Also, seek emergency care if numbness:

• Comes on suddenly.
• Occurs in your “saddle area” (thighs, buttocks and genitals).
• Affects an entire arm, an entire leg or one entire side of your body.
• Occurs below a certain level in your body (for example, below your chest).
• Spreads quickly to other areas of your body.

Most cases of numbness are less urgent, but a healthcare provider should still assess them. Contact your provider if numbness:

• Doesn’t have an obvious cause.
• Occurs during repeated activities/motions.
• Causes loss of strength or muscle control over time.
• Is accompanied by a rash.