eli5 When you stub your toe, why does it take a bit before the pain kicks in?

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eli5 When you stub your toe, why does it take a bit before the pain kicks in?

In: Biology

The body has several different types of pain receptors and they are generally divided into two categories: fast and slow.

Fast pain is transmitted via myelinated A delta fibers and is described as sharp, localized pain. The pain travels at 6 to 30 meters per second. Think of a burn or a cut and how quickly one is able to realize this pain and respond to it.

Slow pain is transmitted via unmyelinated C fibers which is often described as dull, aching, throbbing. Most often associated with joints, muscle tissue, tendons. Velocity of slow pain is 0.5 to 2 meters per second.

This is a very simplified explanation.

The action of stubbing your toe involves blunt injury to the skin and more significant trauma to the tendons, muscles, joints. You’re receiving pain from your C fibers which is why there is a bit of a pause before you feel the pain. Unless you stubbed your toe on a piece of furniture which had a pointy thumb tack sticking out of it which pierced your toe at the same time–then you would activate both your A delta and C fibers. You’d get the rapid pain followed by the deeper slow pain–slow follows fast.