Dear Sara,

Pain is unpleasant, but we need it for survival. Just the other day I was out exploring when I stubbed my paw and let out a big meow. My nervous system was doing its job.

Part of the reason we feel pain is because our bodies have tons of nerves that help us move, think, and feel in all kinds of ways.

When you stub your paw or toe, for example, the nerves in the skin of your toe will send a message to your brain that you are in pain. These messages are what scientists call impulses. They start in your toe, move to your spinal cord, then your brainstem, and onto your brain.

It’s actually your brain that tells you that you’re in pain. And if you’ve ever stubbed your toe, you know this message gets delivered pretty fast. In fact, when you feel pain, sometimes the impulse, or message, will travel at 250 mph. That’s the speed of a very fast racecar.

Screen Shot 2016-04-04 at 9.05.13 AMIt’s important for the message to move fast because you have to make a quick decision about what to do. Sometimes your decision might be a matter of survival—but other times it might be as simple as deciding if you need a bandage, ice pack, or even a trip to the doctor.

Pain is actually the number one reason people see a doctor, said my friend Raymond Quock. He’s a scientist here at Washington State University who is really curious about pain.

“Pain in many aspects is good,” Quock said. “It’s a warning that your body is in danger.”

Most humans can feel pain, but not all humans, he said. Because of genetics or nerve injury, some people can’t feel pain.

Imagine touching a hot pan and not realizing it just came out of the oven. Or imagine if you broke your leg, but didn’t know it. And while that might sound pretty nice, it can also be quite dangerous.

If you didn’t feel pain, you might end up with even more damage to your body. Pain helps tell us when to take extra care of ourselves.

People have different kinds of pain, too. There’s physical pain, emotional pain—even growing pains. The kind of pain Quock studies is called chronic pain. Unlike acute pain, like stubbing your toe, chronic pain is pain that hurts and aches for months or longer.

This kind of pain doesn’t appear to have a very useful purpose. It doesn’t help much with survival. Quock and his team of WSU researchers are investigating why it happens and how to treat it. They are working on some great ideas about how to help patients feel better.

While some pain doesn’t seem to have a purpose, pain definitely does keep us safe in a lot of other potentially dangerous situations. Our nerves help us sense the world around us so we can explore. They can also help remind us to watch where we step next time.

Dr. Universe