Watch out! Today’s Think About it Thursday may have you on pins and needles!

Have you ever thought about…

• Why does my foot fall asleep?
• What do your nerves do?
• What is paresthesia?

Did you know?

You know the feeling. You’ve been sitting down, reading or possibly watching something on tv for half an hour or so, one leg tucked underneath you. You get thirsty and jump up to grab a drink of water. As soon as your foot hits the ground, though…ugh! It feels like you’re walking on pins and needles.

What’s wrong? Your foot has fallen asleep! Was your book or television show that boring? Or did your foot not get a good night’s sleep last night? What’s the deal?

Some people believe that paresthesia — the heavy, dull, tingling, burning or “weird” pins and needles feeling when your foot falls asleep — is caused by not enough blood circulating to your foot. In reality, though, your foot falling asleep has more to do with your nerves. 

Nerves are like tiny wires that run throughout your body. Like the electric wires throughout your house that carry electricity to outlets, your nerves carry messages back and forth between the many parts of your body and your brain. If you sit on your foot long enough, you compress the nerves in that area. Of course, this can happen to other parts of your body, too. People might experience legs, arms and hands that fall asleep from time to time.

When you compress the nerves in a certain area, communication from that part of the body to the brain is disrupted temporarily. As a result, that part of your body doesn’t feel anything because it’s not communicating with your brain. If you also happen to be compressing arteries in that area, blood flow to your nerves may be reduced, too. This can contribute to the mis-communication with the brain.

When you change position, the nerves begin to return to normal and start communicating again. While those connections with the brain are being established again, you feel some weird sensations. They usually don’t hurt, though, and they don’t last very long.

Everyone experiences these feelings from time to time, and they’re completely normal. They don’t hurt your body, but they sure can feel really strange for a short time until your brain and your body start “talking” again!

Think about it a little more…

A limb that’s fallen asleep can sometimes feel like dead weight. Test your knowledge of the body with the Human Body Quiz.