Why paper cuts are so painful

The paper seems harmless, but anyone who refills a copying machine or quickly scrolls through a book knows that this modest material is fraught with an ominous secret. When used properly, it turns into a serious weapon: paper cuts are the worst.

Not so much research has been done on the pain of paper cuts, probably because no one wants to enroll in a controlled experiment with a random sample in which researchers will cut subjects. But according to Dr. Hayley Goldbach [Hayley Goldbach], dermatologist from the University of California in Los Angeles, "for that we can use our knowledge of anatomy. It all depends on the anatomy. ”

It all depends on the nerve endings. There are much more nerve endings in the fingertips than in most other places in your body. True, Goldbach specifies that “probably, it will also be painful if you cut the face or genitals with paper”. So, while cutting a hand, hip, or ankle can be frustrating, it will be more mundane than a hell of a fingertip cut with paper.

This can be experienced with the help of a test used by psychologists and neurologists. Take a paper clip and straighten it so that both ends point in the same direction. If you poke her face or hands with her, you can feel both ends separately. This effect is called two-point recognition. Since there are so many nerve endings in the skin on these parts of the body, in order for you to stop distinguishing between the two ends of the clip, they will need to be brought very close together.

But if you try to poke yourself in the back or legs, most likely, in order to reliably distinguish the two ends of the clip, they will have to be diluted very widely. Nerve endings on these parts of the body are much less common.

This is very evolutionary. “With our fingertips we study the world and perform small and delicate tasks,” explains Goldbach. - It makes sense to have a large number of nerve endings in these places. This is a defense mechanism. ”

It is reasonable that the brain devotes more nerve resources to tracking possible threats to your hands, as they are the main tool for communicating with the world. If you, say, touch something hot or hot, then most likely you will touch it with your hands. Therefore, severe pain from a finger injury is the result of proper evolutionary work, which encourages you to be more careful with your hands.

We turn to the weapon. If you believe Google, then the paper, because of its porosity, serves as a zoo for bacteria, ready to colonize your wounds from cuts. Like it or not, the presence of bacteria or other microorganisms does not explain the pain - at least not at the time of the cut. Bacteria can infect a wound if not treated, and this can be painful, but takes some time.



But still it makes sense that the paper turns out to be an extremely painful weapon.

To the naked eye, the edge of the paper looks straight and smooth. But with the increase it becomes clear that the paper is more like a saw, and not like a blade. And when paper opens the skin, it leaves behind a chaotic path of destruction, not a smooth cut. It breaks and shreds the skin, instead of making a neat cut in the manner of a razor or knife.

In addition, paper cuts are shallow, but not too small. “They are deep enough to go through the top layer of skin, otherwise you would not be hurt. There are no nerve endings in the upper layer of the skin, ”says Goldbach.

But the cuts are not very deep, which is why it is strange that they turn out to be so painful. But precisely because of this property they are so unpleasant. A deeper wound would begin to bleed, the blood would coagulate and form a scab under which the wound would heal without environmental exposure. But shallow wounds do not receive such protection. If you do not cover it with a plaster or a disinfecting ointment, the nerves that were exposed when you cut it with paper will be exposed to surrounding influences, which will disturb them.

Without a pillow from the blood, the pain receptors remain open, and if you cannot cover them quickly, the neurons will send alarm messages to the brain. After all, it is their job.



This is in theory. Nobody has proven that this is the case, but Goldbach agrees that this hypothesis is quite reasonable.

Unfortunately, in life, each of us will have to face several paper cuts. Fortunately, the penalty of " death from a thousand cuts " with the help of paper does not threaten you. It will be painful, but not fatal.