Why do burns hurt so much?

[Zsofia]

I’d imagine pretty much everybody would agree that a burn is the most painful common household injury around, particularly when it comes to the “inches to pain” measurement.

A year or so ago I got a new dishwasher and burned myself on its heating element - it was the tiniest little second degree burn on my knuckle, but the pain was incredible, long-lasting, and life-disturbing. (Couldn’t sleep, etc.) Last night I made a classic spatula error - smacked the handle of the spatula in the bacon-grease pan, it flew up and sprayed screaming hot bacon grease all up in my face. The whole right side of my face hurt like it was eating my brain. Couldn’t sleep at all. Figured I might be disfigured enough by it that I could call in sick at least, right? Woke up this morning and the visible burn is no more than, oh, an inch by half an inch. (Right next to my eye, though.) I assume that there’s more “burn” that isn’t visible, which hurt last night and then got over itself, right?

So what is it that makes even minor burns so painful?

[Der_Trihs]

@Zsofia

So what is it that makes even minor burns so painful?

From my ( layman’s ) understanding, the fact that it IS a minor burn. Pain comes from nerves that are reporting damage; not nerves that have been destroyed. And burns often do damage over a large area, thus making a lot of nerves fire; unlike a cut which tends to be narrow.

So, basically a minor burn like that to your face causes enough damage to set a lot of nerves over a lot of your face screaming, but not enough damage to keep them from firing.

[sandra_nz]

WAG - Plus we tend to get burns in areas where we have lots and lots of nerve endings, e.g. hands

[Snarky_Kong]

@Der Trihs

From my ( layman’s ) understanding, the fact that it IS a minor burn. Pain comes from nerves that are reporting damage; not nerves that have been destroyed. And burns often do damage over a large area, thus making a lot of nerves fire; unlike a cut which tends to be narrow.

So, basically a minor burn like that to your face causes enough damage to set a lot of nerves over a lot of your face screaming, but not enough damage to keep them from firing.

I’m pretty sure there’s more to it than this. I’ve injured myself with a belt sander. That covered a fairly large area. I suppose it might have destroyed a lot of the nerves, but burn pain is so much different than cuts or bruises. Cuts are very sharp and burns are throbbing.

[Zsofia]

@sandra_nz

WAG - Plus we tend to get burns in areas where we have lots and lots of nerve endings, e.g. hands

On the other hand, a good sunburn on your shoulders will definitely keep you up at night.

ETA - and when I was a kid and would scrape my knees and stuff, it never ever had the kind of pain associated with it that a similar minor burn would have had. Interestingly, a “carpet burn” is more similar (but not nearly the same.)

[RedSwinglineOne]

From WikiAnswers

Why do burns hurt so much i.e. more than cuts?

Burns hurt because when the skin is burned, the skin tries to get rid of the heat as fast as possible. It does this by all the capillaries opening wide (most of them usually aren’t). But when they stay wide open too long, they rupture, causing further damage, and sometimes tissue death.

Cuts hurt too, but the deeper the cut, the less it hurts. Most of the nerves in your skin are loacted along the more shallow layers of skin (this is also why a paper cut can hurt a lot more than a more serious deep cut). A deeper cut severs nerves…no nerves, no pain.

I don’t find this answer very satisfying.

My WAG is going to be that while most cuts or bruises only stimulate nerves in the exact areas that have been damaged, burns stimulate all the nerves in the general area that received heat, whether there was damage or not. Not so much as a sign of damage, but as a ‘don’t do that again.’

[Peter_Morris]

Pain is a feature that stops you from doing damage to yourself. You do something stupid, you get burned. The pain is your body’s way of telling you, “hey, idiot, don’t do that again.”

If it didn’t hurt so much, you wouldn’t care, or might not even notice getting burned. You could splash hot fat in your face every day of the week, and not feel it. Of course, you would cook your flesh.

I’m sure you have learned from your experience. You won’t be touching any more heating elements for a while. And next time you cook, you’ll be extra careful with the spatula, right? That’s what the pain has done for you.

[Yllaria]

Are there separate heat sensing nerves in addition to the pain sensing nerves? And if so, do both fire off when you get burned? If that’s the case, that could double the signal.

I’m working from a vague memory, here.

[Snarky_Kong]

@Peter Morris

Pain is a feature that stops you from doing damage to yourself. You do something stupid, you get burned. The pain is your body’s way of telling you, “hey, idiot, don’t do that again.”

If it didn’t hurt so much, you wouldn’t care, or might not even notice getting burned. You could splash hot fat in your face every day of the week, and not feel it. Of course, you would cook your flesh.

I’m sure you have learned from your experience. You won’t be touching any more heating elements for a while. And next time you cook, you’ll be extra careful with the spatula, right? That’s what the pain has done for you.

You completely missed the point of the question. You get pain from stabbing yourself too, but the pain from a burn is much worse, why?

[Roadfood]

@Peter Morris

Pain is a feature that stops you from doing damage to yourself. You do something stupid, you get burned. The pain is your body’s way of telling you, “hey, idiot, don’t do that again.”

If it didn’t hurt so much, you wouldn’t care, or might not even notice getting burned. You could splash hot fat in your face every day of the week, and not feel it. Of course, you would cook your flesh.

I’m sure you have learned from your experience. You won’t be touching any more heating elements for a while. And next time you cook, you’ll be extra careful with the spatula, right? That’s what the pain has done for you.

This does nothing to explain what the physiological mechanism is that results in burn pain being so much worse than other pains. That’s what the OP is asking.

[Scylla]

I got badly burned 1st, 2nd and 3rd on both hands as a kid. The facts as I recall them were that the actually burning wasn’t all that bad. It hurt a lot, but no worse than other severe sharp pains. The actual parts with 3rd degree burns didn’t hurt at all. they still have no feeling today. Those nerves dies.

It was several minutes later that the pain started building.

It’s been almost 30 years but this is the way it was explained to me at the time:

Some of that building that pain is the final swan song of dying nerves. Some of the pain are the adjacent good nerves receiving and relaying the dying nerves’ signals on top of their own.

The reason a burn hurts so much more than most anything else is that is a different kind of damage than most anything else. Most trauma, involves losing a piece or severing a piece. Let’s say you get a chunk taken out of your arm. All the nerves in that chunk are gone. You no longer feel any pain from them. You receive the pain from the nerves that are damaged and severed at the point of the wound, and the ones next to them. That’s all.

With a burn though the damage is usually diffuse. The chunk is still there, but it is all beaten up and damaged and the whole thing is basically still transmitting. Some of the parts burned dead, aren’t but the damaged and dying ones are all still there and transmitting.

Think of it this way: In a normal wound you have a two dimensional surface where the damage is transmitting pain. In a burn that is now a three dimensional mass.

You are cubing the pain, literally taking it to the next power when you go from a wound to tissue damage.

As your body reacts to the wound it makes matters more painful both as a consequence of the healing process and also to protect it. Your body does not want you messing with that burned part and let’s you know that it’s off limits.

Nerves are dying, damaged ones are sending screaming pain signals. Your body is sending tons of blood and fluids and plasma to the damaged area which causes swelling and pressure further aggravating the damaged nerves.

This so far takes an hour or so to ramp up to full bore, IIRC. It takes this long for your body to figure out how badly it’s been damaged and build up the appropriate response.

It gets worse and different about 12 hours later as an immune response starts to kick in. You now have a bunch of dead and damaged tissue interspersed with living tissue. This tissue will turn into an extremely painful infection that could potentially spread and kill you. Some of will spread and healthy tissue will die, causing new and fresh pain as time goes on. Your body doesn’t wait for this. It treats that dead tissue as foreign and works to encapsulate it and destroy it. It’s not particularly discriminating, either in this process, either and living tissue may also get attacked and destroyed causing new pain. The swelling and pressure and damage may shut off blood flow and support to undamaged areas, causing them to begin to suffer and die and they will send pain signals. Fresh tissue and nerves may begin to heal and these will be very sensitive and they will transmit their sensitivity like a newborn child screaming in the middle of a street riot.

This goes on for about six weeks or so.

The two things that hurt the worst were when about two hours after the burns, they had to wash them to remove dead tissue and clean out foreign matter and contaminants. I was pretty heavily medicated and not feeling particularly bad at that moment.

They didn’t mess around. I was wondering why they had five huge orderlies all holding on to me; arm, arm, leg, leg, body since I was being perfectly cooperative. Then the water hit my hands, and I began to scream and the orderlies had their hands full.

That hurt the worst.

The second worst pain was the periodic scraping of the scabs and scar tissue to minimize the forming of keloid or cross-hatched scarring.

The ongoing pain of the burns wasn’t always bad. It was like surfing where it come in waves and build and then fade some. The top of the waves was pretty bad, but supposedly there’s only so much pain at so much intensity that you can actually feel before you overload. Than it kind of has to recharge before it can feel unbearable again. These cycles seemed to take about half an hour at first, but over days would go longer with the highs being not quite as high but the lows being quite as low. After a week or so, it was pretty close to a steady state.

Mixed in there were the effects of the drugs they gave me for pain which whose effectiveness would cycle up and down as they wore off. These started off pretty generous but I was young and they didn’t want to addict me and after 24 hours they got pretty stingy with them, and only got generous right before treatments. The way it seemed to me was that the medication didn’t really make anything numb, it was like a sponge that could absorb only so much before it overflowed. Usually pretty quickly into the procedure it would feel like it had all been used up and they were working on me unmedicated.

I am told, and I believe, that this isn’t how it works. It would have been a lot worse without medication. Didn’t seem that way, though.

[Forest Gump] and that’s all I have to say about that[/Forest Gump]

[Zsofia]

Jesus, Scylla, that sucks.

[revconguy]

Lurker here…gotta know…

Scylla, sounds horrible. I’ve heard many horrifying stories of the burn cleaning or debrieding process. Why don’t they knock people out first instead of making them endure the painful process?

@Scylla

I got badly burned 1st, 2nd and 3rd on both hands as a kid. The facts as I recall them were that the actually burning wasn’t all that bad. It hurt a lot, but no worse than other severe sharp pains. The actual parts with 3rd degree burns didn’t hurt at all. they still have no feeling today. Those nerves dies.

It was several minutes later that the pain started building.

It’s been almost 30 years but this is the way it was explained to me at the time:

Some of that building that pain is the final swan song of dying nerves. Some of the pain are the adjacent good nerves receiving and relaying the dying nerves’ signals on top of their own.

The reason a burn hurts so much more than most anything else is that is a different kind of damage than most anything else. Most trauma, involves losing a piece or severing a piece. Let’s say you get a chunk taken out of your arm. All the nerves in that chunk are gone. You no longer feel any pain from them. You receive the pain from the nerves that are damaged and severed at the point of the wound, and the ones next to them. That’s all.

With a burn though the damage is usually diffuse. The chunk is still there, but it is all beaten up and damaged and the whole thing is basically still transmitting. Some of the parts burned dead, aren’t but the damaged and dying ones are all still there and transmitting.

Think of it this way: In a normal wound you have a two dimensional surface where the damage is transmitting pain. In a burn that is now a three dimensional mass.

You are cubing the pain, literally taking it to the next power when you go from a wound to tissue damage.

As your body reacts to the wound it makes matters more painful both as a consequence of the healing process and also to protect it. Your body does not want you messing with that burned part and let’s you know that it’s off limits.

Nerves are dying, damaged ones are sending screaming pain signals. Your body is sending tons of blood and fluids and plasma to the damaged area which causes swelling and pressure further aggravating the damaged nerves.

This so far takes an hour or so to ramp up to full bore, IIRC. It takes this long for your body to figure out how badly it’s been damaged and build up the appropriate response.

It gets worse and different about 12 hours later as an immune response starts to kick in. You now have a bunch of dead and damaged tissue interspersed with living tissue. This tissue will turn into an extremely painful infection that could potentially spread and kill you. Some of will spread and healthy tissue will die, causing new and fresh pain as time goes on. Your body doesn’t wait for this. It treats that dead tissue as foreign and works to encapsulate it and destroy it. It’s not particularly discriminating, either in this process, either and living tissue may also get attacked and destroyed causing new pain. The swelling and pressure and damage may shut off blood flow and support to undamaged areas, causing them to begin to suffer and die and they will send pain signals. Fresh tissue and nerves may begin to heal and these will be very sensitive and they will transmit their sensitivity like a newborn child screaming in the middle of a street riot.

This goes on for about six weeks or so.

The two things that hurt the worst were when about two hours after the burns, they had to wash them to remove dead tissue and clean out foreign matter and contaminants. I was pretty heavily medicated and not feeling particularly bad at that moment.

They didn’t mess around. I was wondering why they had five huge orderlies all holding on to me; arm, arm, leg, leg, body since I was being perfectly cooperative. Then the water hit my hands, and I began to scream and the orderlies had their hands full.

That hurt the worst.

The second worst pain was the periodic scraping of the scabs and scar tissue to minimize the forming of keloid or cross-hatched scarring.

The ongoing pain of the burns wasn’t always bad. It was like surfing where it come in waves and build and then fade some. The top of the waves was pretty bad, but supposedly there’s only so much pain at so much intensity that you can actually feel before you overload. Than it kind of has to recharge before it can feel unbearable again. These cycles seemed to take about half an hour at first, but over days would go longer with the highs being not quite as high but the lows being quite as low. After a week or so, it was pretty close to a steady state.

Mixed in there were the effects of the drugs they gave me for pain which whose effectiveness would cycle up and down as they wore off. These started off pretty generous but I was young and they didn’t want to addict me and after 24 hours they got pretty stingy with them, and only got generous right before treatments. The way it seemed to me was that the medication didn’t really make anything numb, it was like a sponge that could absorb only so much before it overflowed. Usually pretty quickly into the procedure it would feel like it had all been used up and they were working on me unmedicated.

I am told, and I believe, that this isn’t how it works. It would have been a lot worse without medication. Didn’t seem that way, though.

[Forest Gump] and that’s all I have to say about that[/Forest Gump]

[sturmhauke]

That sounds like pure torture. Did your flesh grow back, or do you have pieces missing?

[Scylla]

@sturmhauke

That sounds like pure torture. Did your flesh grow back, or do you have pieces missing?

I didn’t lose chunks. It grew back. The cuticles are wrong, and there’s scar tissue. They actually look pretty ok unless you look close. Lost some feeling and some dexterity. They are just king of ugly.

[Zsofia]

I don’t want to be rude or nosy, but what happened? Stove accident? Runaway fireworks truck? Motorcycle jump through flaming ring gone horribly wrong?

[Crescend]

@Yllaria

Are there separate heat sensing nerves in addition to the pain sensing nerves? And if so, do both fire off when you get burned? If that’s the case, that could double the signal.

I’m working from a vague memory, here.

There are two separate sets of temperature sensors (thermoreceptors), ‘heat’ receptors (25C-45C, connected to small, insulated A(delta)-fibers) and ‘cold’ receptors (12C-37C, connected to small, uninsulated C-fibers).

The pain sensors (nociceptors) also have two sets of detectors relevant to this discussion. The ‘fast’ thermal nociceptors (well-localized, sharp pain) are connected to A(delta) fibers, trigger when temperature goes out of range (5C-45C). There are also ‘slow’ polymodal nociceptors, connected to C-fibers, that can get triggered by a whole bunch of stimuli (chemical, mechanical, thermal), and are associated with poorly localized, dull, burning or aching pain.

[FourPaws]

I do assume that like everything else, you can get used to the pain from burns. I myself would prefer to get burned any day rather than cut. I generally burn myself about 60x a year on a conservative average (woodstove, range, etc). Some are accidental, some – I just don’t care. I’m too lazy to grab a potholder, etc.

[Merijeek]

@FourPaws

I do assume that like everything else, you can get used to the pain from burns. I myself would prefer to get burned any day rather than cut. I generally burn myself about 60x a year on a conservative average (woodstove, range, etc). Some are accidental, some – I just don’t care. I’m too lazy to grab a potholder, etc.

There’s a Mexican restaurant near my house. When the food is served, the little Mexican lady brings it over from the window where the cook (who is never seen!) puts it.

I swear, I’ve got fairly pain-deadened hands, and if I hold my hand within an inch of those plates it’s so hot that it’s extremely uncomfortable. Our little waitress carries those things over bare-handed.

My SO is convinced that she “only touches them with the tips of her fingers so it doesn’t hurt so much”. To me, it doesn’t see like it would hurt any less, it would just hurt smaller areas…

-Joe

[FourPaws]

@Merijeek

There’s a Mexican restaurant near my house. When the food is served, the little Mexican lady brings it over from the window where the cook (who is never seen!) puts it.

I swear, I’ve got fairly pain-deadened hands, and if I hold my hand within an inch of those plates it’s so hot that it’s extremely uncomfortable. Our little waitress carries those things over bare-handed.

My SO is convinced that she “only touches them with the tips of her fingers so it doesn’t hurt so much”. To me, it doesn’t see like it would hurt any less, it would just hurt smaller areas…

-Joe

Sorry for the delay in responding.

I am sure she has some mean calluses on her fingertips, which slows down the time for pain response (the fingertips have to heat up). My callouses on my fingertips are thick enough that they will occasionally crack in low humidity. But, it’s nice to have them when holding hot items. Taking steel pans out of the over, don’t use pot holders. Glass ones, I will. glass and ceramic hold the heat longer as they are heat sinks. When working in a restaurant, we used to take ceramic dishes out of the oven and set them on the counter and remove the contents. If you didn’t pay attention, you would then try to pick up the dish someone else has set there not five seconds before. You couldn’t hold the dish; not because you felt the heat, but because it was so hot it would literally melt/burn your fingertips so fast it would slip out like your fingertips were greased.

However, it is nice having those callouses when red hot coals fall out of my wood stove at the house. I just pick them up the coals with my fingertips and chuck them back in the fire.