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Why Do I Have Numbness in My Legs?

Medically Reviewed by Sabrina Felson, MD on May 15, 2021

When your legs feel numb, it could be due by anything from sitting in one position too long to nerve damage from diabetes. Learn about the possible reasons it's happening and find out what you need to do about it.

Paresthesia

If you sit or have your legs crossed for too long, the pressure can briefly compress nerves in your leg. That prevents your brain and the nerves in your leg from "talking" to each other like they should. The term for this is paresthesia, but most people say their leg (or other body part) has "fallen asleep."

If paresthesia is the reason for your leg numbness, you may also notice:

  • Burning
  • Tingling
  • A feeling that your skin is "crawling"

Once you move your leg, the numbness should go away. You can prevent paresthesia if you change your sitting positions often and try not to cross your legs for too long.

Sciatica

Your sciatic nerve runs from your lower back, through your hips and butt, and down your legs. If it gets pinched, it can cause your leg to go numb.

Sciatica often affects one side of your body. You're more likely to have it if you sit for a long time, have extra body weight, or are in an older age group.

Besides leg numbness, you might have:

  • Pain that spreads from your lower back down the back of your leg, often described as a shooting pain down the back of the leg below the knee and even into the toes.
  • Pain that gets worse when you cough, sneeze, or sit for a while
  • Muscle weakness
  • Tingling

Mild sciatica sometimes goes away on its own. If yours lasts more than a week, began after an accident, or you start to lose control of your bladder or bowels, check with your doctor.

Some drugs, like anti-inflammatories or steroid shots, can ease your pain. Physical therapy often helps, too. In severe cases, you may need surgery to take pressure off the nerve.

Diabetes

High blood sugar -- over a long period of time -- can damage the nerves throughout your body. The numbness most often starts in your toes, and then slowly moves upward. It is usually in both feet.  You may hear your doctor call this peripheral neuropathy. Your hands and arms may also become numb, and you'll notice this gets worse at night.

If peripheral neuropathy is the cause of your tingling, you might also have:

  • Intense leg pain
  • Muscle weakness
  • Weak reflexes­ (often at the ankle)
  • Trouble with balance
  • Foot sores or infections
  • Pain when touched

Call your doctor if you have signs of diabetes-related leg numbness. You might need help to better control your blood sugar. If you ignore it, nerve damage can raise your chances of hurting your foot from things like stepping on a splinter or repeatedly stubbing your toe. Over time, frequent foot injuries can lead to painful joints.

Multiple Sclerosis

Numbness is a common early symptom of multiple sclerosis (MS). If you have this condition, your immune system -- the body's defense against germs -- attacks your central nervous system. Your leg could have a "pins and needles" feeling, or the numbness could be so severe that you can't feel your foot and struggle to walk.

No two people with MS have the same symptoms, but you may also notice:

When MS is the cause, the numbness in your leg could come and go. Prescription steroids could help you get through a flare faster. If you don't know if you have MS, talk to your doctor. Although there's no cure, early treatment might keep the disease from getting worse.

Peripheral Nerve Tumor

Rarely, a tumor called a peripheral nerve tumor can grow in or near the nerves that control the muscles in your legs. It's usually benign, which means it's not cancer. But it can cause nerve damage and pain.

If you have a tumor, other signs may be:

  • Swelling
  • A lump under your skin
  • Muscle weakness
  • Loss of balance

Your doctor may choose to watch the tumor if it is slow-growing. In some cases, they may recommend surgery to remove it or chemotherapy or radiation.

WebMD Medical Reference

Sources

SOURCES:

Mayo Clinic: "Diabetic Neuropathy," "Peripheral Artery Disease (PAD)," "Peripheral Nerve Tumors," "Sciatica," "Numbness."

National Multiple Sclerosis Society: "Numbness or Tingling," "MS Symptoms," "Definition of MS."

American Heart Association: "About Peripheral Artery Disease (PAD)."

UPMC: "Health Beat: Why does my foot fall asleep?"

Supplement to Journal of Managed Care Pharmacy: "The Importance of Early Diagnosis of Multiple Sclerosis."

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