Numbness is a symptom of many things, including just sitting in an odd position, so don’t dial 911 just because you temporarily lose feeling in your foot. But if one of your body parts has fallen asleep and can’t get up, it’s possible one of these conditions is throwing you out of whack.

Your immune system is attacking you

The first symptoms of Guillain-Barre syndrome are often “weakness and tingling in your extremities,” according to the Mayo Clinic. “These sensations can quickly spread, eventually (paralyze) your whole body.” That weakness could make it hard to walk, swallow your food and control your bladder or bowels. It could also come with a quick heartbeat, blood pressure changes and a hard time breathing.

Doctors don’t know exactly what causes this condition, in which your immune system targets your nerves, but many people have a respiratory infection or a stomach flu right before they come down with it.

Read: 5 Everyday Things That Can Make You Faint

You have a Biblical disease

Leprosy was a dreaded disease in ancient civilizations and it still hits us today with symptoms that include, in addition to numbness, skin growths and lesions, enlarged nerves, pain and muscle weakness. The bacterial infection can cause permanent damage if left untreated.

You are not getting enough vitamin B12

Vitamin B12 deficiency can present with numbness or tingling in your hands, legs and feet, and it can also come with trouble thinking, memory loss, weakness and fatigue, anemia, a swollen tongue, difficulty balancing, or even hallucinations, Harvard Medical School says. We need the vitamin to help us make red blood cells, among many other bodily functions, but we may not get enough of it in our diet. According to Harvard, vegetarians are particularly at risk because plants don’t make B12: “Strict vegetarians and vegans are at high risk for developing a B12 deficiency if they don’t eat grains that have been fortified with the vitamin or take a vitamin supplement.”

You have a genetic mutation

Charcot-Marie-Tooth disease is inherited and causes nerve damage as well as weak muscles. “Symptoms usually begin in your feet and legs, but they may eventually affect your hands and arms,” the Mayo Clinic says. “Foot deformities such as hammertoes and high arches are also common.”

People who have inherited the disease have genetic mutations that damage the nerves in their extremities or the protective layer around those nerves, making it harder for your brain to communicate with those parts of your body.

“That means some of the muscles in your feet may not receive your brain's signal to contract, so you're more likely to trip and fall,” the Mayo Clinic says. “And your brain may not receive pain messages from your feet, so if you've rubbed a blister on your toe, for example, it may get infected without your realizing it.”

See also:

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