Why do paper cuts hurt so much?

We all know the agonizing feeling. 

We're reading a book or opening an envelope when, all of a sudden, there's a sharp pain on our finger.

You see a little bit of blood and realize you've just gotten a paper cut.

Paper seems so light, flimsy and harmless. Yet they cause cuts that are extremely painful - and can be for days.  

Dr Hayley Goldbach, a resident dermatologist at UCLA Health, spoke to DailyMail.com about why paper cuts are so jagged, how the element of surprise leaves us in more pain and how to make sure they heal quickly.

Dr Goldbach explained that one reason paper cuts hurt so much is where they occur: primarily on the finger.

'We have nerve endings all over the body,' she said. 'In places where there is refined movement and sensation - like the lips or tips of the fingers - they have a high density of nerve endings.' 

These nerve endings are known as nocireptors and they send signals to the brain about things that could cause a break in the skin, such as extreme hot or cold temperatures and chemicals. 

Dr Goldbach says you can test this by unfolding a paper clip so both ends are facing the same direction like prongs.

If you poke your finger, you can discern the two individual ends. However, if you poke yourself in the back with the same unfolded paper clip, it would be harder to tell the two ends apart.

'That's because the back has a lower density of nerve endings,' she said. 

Another reason why paper cuts hurt so much is that you're using your hands throughout the day, meaning that the wound is constantly getting opened.

'You often get paper cuts on the pad or tip of the finger, different from where you'd get a knife cut,' said Dr Goldbach.

'It's hard not to use your hands, so there's constant pressure on the wound without a chance for it to heal.'

The paper itself is another reason why these superficial cuts leave us in so much pain.

Paper might look and seem smooth but, if you study it under a microscope, the edge is actually jagged. 

'Paper is quite sharp, jagged - it's a bit of serrated edge,' said Dr Goldbach. 'It cuts you pretty quickly before you have a chance to realize it.'

This, in turn, leaves behind a cut that is jagged rather than smooth.

Additionally, paper is made from wood pulp, cotton and other fibers, which can be left behind in the wound.

This is different from being cut by a knife or a razor, both of which leave little material behind that can sting the cut. 

'Paper can contain fibers that are inflammatory, which is why it's important to run [the cut] under water and wash it with a little soap,' said Dr Goldbach.

Additionally, paper cuts are quite shallow, which makes them even more annoying to deal with.

When the body has a deep cut, blood clots to prevent bleeding and then a scab forms to protect it.

But paper creates cuts deep enough to reach the nocireceptors but not deep enough to trigger the clotting mechanism, meaning it takes longer for new skin to replace the dead cells.  

Dr Goldbach added that there are mental and emotional elements that cause paper cuts to hurt more than other cuts.

'There's the psychological element of surprise, that it happens so quickly that you don’t have time to withdraw [your hand[,' she said.

'With some other injuries, you feel pressure so you have time to react.'

She also added that because we don't expect to hurt ourselves while working with paper, the surprise of cuts leaves us in further pain. 

'We tend to be careful with a knife - you're being careful on purpose because you know there's a danger,' said Dr Goldbach.

While we're careful with knives, we're not so careful with paper. 

'There's not as much of an element of surprise when you get cut. But with paper, it's absolute surprise because you don't expect to be hurting yourself.' 

If you do get a paper cut, Dr Golbach recommends washing it with soap and water and putting a band-aid on it.

'You want to make sure it's clean and covered to prevent re-traumatizing it,' she said. 

Dr Goldbach also suggests to not believe the old wives' tale that claims cuts heal faster if left uncovered because they form scabs.  

She says wounds that are kept moist under a bandage will be less painful and will replaced the damaged skin cells more quickly with new ones  

'Wounds like to be moist when they heal, it helps them heal quicker,' she said. 

Dr Goldbach added that paper cuts don't have high rates of infection - in fact, it happens so rarely that there are no available statistics - but warns that there are situations in which you should seek medical attention.  

'If it's red, if there's drainage, it looks contaminated or infected, see a doctor immediately,' she warned. 

Source: The Daily Mail

Follow NEWS.am Medicine on Facebook and Twitter