Name: 為什麼我們會有疼痛，以及如何消除疼痛？ (Why We Have Pain, & How We Kill It)
Uploaded: 2021-01-14T06:32:18.000Z
Duration: 10 min 5 s

Pain is generally considered to be an unpleasant thing, no one likes the sensation of a pounding headache or a broken collar bone,

疼痛通常被認為是一件很不舒服的事，沒有人喜歡劇烈頭痛或鎖骨斷掉的感覺，

so there has always been a market for analgesics or pain-killing remedies.

所以止痛藥或鎮痛治療從來都不缺市場。

Ancient Egyptians munched on myrtle leaves and smoked opium, Native Americans chewed up strings of willow and birch bark to dull their pain.

古埃及人用力咀嚼紫薇葉及吸鴉片來緩解疼痛，美洲原住民則是啃咬柳樹條和樺木皮。

Today there are all sorts of pills that could make painful situations more bearable

現在有各式各樣的藥丸可以緩解疼痛症狀，

but to understand how these things do their job,

但是要了解這些藥物如何發揮功效，

it helps to first get a handle on why we have physical pain at all, how it works

我們必須先了解為什麼我們會有生理痛，這些疼痛怎麼來的

and why we feel it so often like right now, the lights... in my eyes... its been a long day

還有為什麼我們這麼常感覺到疼痛，就像現在，光線照到我的眼睛... 噢真是漫長的一天。

Although most of us go to great lengths to avoid it,

雖然大部分人用盡全力想擺脫疼痛，

pain is good for us because it helps us protect ourselves from the world!

但是疼痛其實是有益處的，因為它能保護我們！

Pain means the body is damaged or under distress. It keeps us from doing stuff

疼痛代表我們身體遭受傷害或是危難。它藉由凸顯缺乏利己這個事實

that is not in our self interest by making that lack of self interest very obvious

來防止我們繼續做非利己的行為。

"Ouch!" is your brain saying "STOP!! Back away from the flame or porcupine or wasp nest

「噢好痛！」其實是你的大腦在告訴你「停！遠離危險的火團、豪豬和蜂巢！

and it's often the earliest sign of when our bodies are under attack by disease.

而當我們受到疾病入侵時，疼痛往往是最初期的徵兆

This is why one of the most dangerous, but extremely rare conditions can be an inability to feel pain.

這就是為什麼無痛症是一種非常危險的罕見疾病之一

Take, for example (United States) Georgian teenager Ashlyn Blocker

拿喬治亞州(美國)的一位青年Ashlyn Blocker來當例子

she has a mutation on a gene called SCN9A, that

has left her with a congenital insensitivity to pain.

She's run around on a broken ankle for days

她拖著受傷的腳踝到處亂跑好幾天

fished dropped spoons out of pots of boiling water, and nearly chewed her own tongue off accidentally.

赤手撿起掉進沸水裡的湯匙，還差點不小心咬斷自己的舌頭

Sometimes other medical conditions can interfere with the body's ability to feel pain.

有時候部分疾病也會干擾痛覺感知能力

The bacterial infection, Leprosy, for example, leaves infected nerves and tissue dead.

好比說，細菌感染和痲瘋病會使受感染神經及組織壞死

So contrary to lore, leprous fingers don't just fall off,

與傳統認知不同的是，痲瘋病患者的手指不只是喪失功能

rather they sometimes sustain great damage because they're numb and have to be amputated.

失去痛覺可能會對他們造成巨大傷害，甚至需要截肢

Thankfully, conditions like this are exceptionally rare because our whole nervous system is

不過幸好，這種情況是非常罕見的，因為我們的神經系統

set up to make sure that pain is the first response to any damage to our bodies.

就是為了確保身體在受損後能立即產生痛覺而設立的

Our nerve receptors are constantly picking up on all kinds of sensations, but we've got specialized receptors called Nociceptors

我們的神經受器可以不斷接收各種感知，但我們有專門在處理痛覺反應的「痛覺感受器」

that unlike those receptors that help you enjoy kitten kisses, only fire to indicate pain.

不同於其它讓你享受跟小貓親親的受器，它只作用在感知疼痛上

For example, if you hold a needle lightly into your palm, you can feel the point, but it doesn't hurt

舉例來說，如果你拿針輕輕地刺你的手掌，你會感覺有尖物，但不會痛

because only your normal nerve receptors are reading the needle.

因為這時只有普通神經受器在感知而已

But if you start slowly pushing on the needle, at some point, it'll hit the nociceptive threshold

但如果你慢慢地把針推入，到某個點的時候，它會戳到痛閾(指引起疼痛的最低刺激量)

The pain hopefully makes you stop digging the needle into your flesh.

這股痛覺就希望你別再繼續把針刺進你的肉裡

Now if the pain is the result of something more severe

如果是一些嚴重意外所造成的疼痛

like tissue or cell damage from falling on your tail bone or slicing your finger on the can opener

像是跌坐撞到尾骨，造成組織或細胞受損，又或是被開罐器削到手指

your body starts sending waves of tuning chemicals to your bruised bum or bloody finger.

你的身體會開始傳送大量化學調節物質，到你瘀青的屁股或是流血的手指

These chemicals lower your nociceptor pain receiving threshold even more.

這些化學反應大大降低痛覺門檻(痛閾)

That's why if you touch a cut or other open wound BARELY, it hurts more.

這就是為什麼你只是碰一下傷口，就會這麼痛

Those tissues have higher levels of tuning chemicals that warn against further damage.

這些組織有高度的化學調節反應，以警告我們避免受到更多的傷害

Kind of like adding insult to injury, I know, but these chemicals are not only the root causes of our pain,

我知道這有點像在傷口上撒鹽，但是這些化學反應不只是造成疼痛的根源而已

they're also the targets that scientists look for to kill the pain.

它們也是科學家研究如何消除疼痛的目標

Think of these compounds as locks and keys.

One of the main chemicals that damaged cells release into your body is called arachidonic acid.

其中受損細胞釋放的化學成分之一就是花生四烯酸

Its job is to interact with two enzymes known as COX-1 and COX-2.

它的功能在於促進COX-1和COX-2兩種作用酶之間的交互作用

When the arachidonic acid combines with enzymes, they form compounds that do things like

花生四烯酸跟作用酶結合，形成的混和物

cause swelling, raise your body temperature and heart rate, and lower that pain threshold

會引起腫脹、體溫升高、心跳加速以及降低痛閾

everything that we associate with being hurt.

任何我們受傷時會聯想到的反應

So if we can keep the arachidonic acid from being the key that fits into those enzyme locks,

所以如果我們能防止花生四烯酸這把鑰匙插進那些作用酶鎖

we can control the effects that these chemicals cause.

我們就能控制這些化學反應造成的影響

To do that, we send in pain killers to block those locks.

為了做到這一點，我們用止痛藥來封住鎖孔

First, you got your friendly hardworking, over-the-counter variety.

第一，你可以在你家附近提供親切服務的藥局買到非處方藥

You'll find them in your medicine cabinet, purse, or tiny package of two pills at a gas station for like five freakin' bucks.

你可以在你的醫藥箱或錢包裡找到它們，或是在加油站買到小包裝兩顆藥丸，而且只賣他*的五塊錢

The second family is made up of the big gun Opioid drugs.

第二種則是由眾所皆知的「鴉片」製成的止痛藥

The kind that only doctors can prescribe, like morphine and oxycodone,

像是嗎啡和氧可酮這種只能透過醫生開處方箋取得

the ones that people keep getting addicted to these days.

也是現在越來越多人吃上癮的藥品

You're not popping these babies for a little headache. They're for severe, nail-through-the-foot, hernia surgery, crap-oh-crap pain.

你不會因為一個小頭痛就服用這類藥品，它們是在很嚴重的情況，諸如：釘子插進腳裡、疝氣手術，在痛死人的時候用的

The first over-the-counter group is known as Nonsteroidal anti-inflammatory drugs, or NSAIDs.

非類固醇抗炎藥(NSAIDS)是第一種非處方藥

They block that flood of pain chemicals, but they don't know exactly how to find the exact site of the pain,

它們緩解大量的疼痛，正因它們不知道實際疼痛位置

so they just block all of those pain signaling Cox enzymes, preventing them from sounding the pain alarm.

所以它們阻擋所有環氧化酶接收疼痛指令

Aspirin, also known as Acetylsalicyclic Acid, was first isolated by German chemist, Felix Hoffmann in 1897

德國化學家費利克斯·霍夫曼，在1897年率先壟斷阿斯匹靈，也就是乙醯水楊酸

for the Bayer company, and its key pain relieving compound is Salicin

給拜耳公司，而阿斯匹靈的關鍵緩痛混和物就是水楊素

And that is found in that Willow Bark that our ancestors were munching on back in Hippocrates' day.

水楊素是在希波克拉底(醫藥之父)的年代下，祖先們嚼咬的柳樹皮裡發現的

Salicin metabolizes into Salicyclic Acid, which disables the Cox-1 enzyme particularly well.

水楊素代謝成水楊酸之後，能有效使 Cox-1作用酶失效

Here, Aspirin is working like a key that breaks off in the lock, that blocks all other keys from getting in.

阿斯匹靈就像是斷在鎖孔裡的鑰匙，防止任何其他鑰匙插入

This means no pain-increasing arachidonic acid gets into the enzymes,

這就代表增加疼痛的花生四烯酸無法再與任何化學酶結合

which means no pain for as long as those blocked enzymes are in your system.

也代表只要那些被擋住的化學酶還在你的體內，你就不會感覺到疼痛

Ibuprofen, often marketed as Advil and Motrin, was first derived from Propionic Acid in the 1960s

布洛芬在1960年代第一次從丙酸裡提煉出來，常見的品牌有Advil(安舒疼)和Motrin(莫疼)

and it works a little differently from other NSAIDs.

而它的原理跟其他非類固醇抗炎藥不太一樣

It blocks arachidonic acid from getting into the enzyme sights responsible for pain, but rather than permanently breaking off like aspirin,

布洛芬阻擋產生疼痛的作用酶接收到花生四烯酸的信號，不像阿斯匹靈一樣永久佔據鎖孔

Ibuprofen just sort of sits there for a while and is eventually spit out by the enzyme block.

它們只是短暫停留，最後還是會被作用酶排出

Naproxen Sodium, including the drug Aleve, is another class of NSAID that also works by inhibiting Cox enzymes.

萘普生鈉片，包括Aleve止痛藥，是另外一種非類固醇抗炎藥，也是靠抑制環氧化酶止痛

Finally, Acetaminophen, or paracetamol, commonly branded as Tylenol, is an over-the-counter drug

最後一種，乙醯胺酚或作撲息熱痛，常見的品牌為泰諾，是一種不同於非類固醇抗炎藥

that is not an NSAID. It only takes effect after the tuning chemicals have bonded with the enzymes

的成藥，它只作用在調節性化學物質和作用酶結合之後

and it inhibits some, but not all, of the effects caused by the compounds they form.

它對結合後產生的影響能起抑制作用，但並非完全抑制

That's why it helps relieve pain and fever, but doesn't reduce inflammation.

這就是為什麼它能解熱、鎮痛，卻無法消炎

Acetaminophen is made from coal tar and is mostly metabolized in the liver

乙醯胺酚是由煤焦油提煉而來，最後會由肝臟代謝掉

So, yeah, if you have too much of it, it can do some liver damage.

沒錯，因此如果你服用過量，可能會對肝臟造成傷害

But sometimes pain might transcend anything your medicine cabinet can ease,

但有時不論是什麼藥品，都可能無法緩解你的疼痛

after, say, your friend accidentally backs over your foot in their mini-cooper.

這麼說好了，你的朋友開著他的mini-cooper倒車，不小心輾過你的腳 (譯註: mini-cooper為一種迷你汽車)

That's when you might want to see a doctor about some prescription pain killers.

這時候你可能會想去請醫生開止痛藥給你

Opioids do business in a completely different way from NSAID's.

鴉片的作用原理跟非類固醇抗炎藥完全不同

They're kind of like silver-tongued pep-talkers, and humans have been using them medicinally and

它們有點像三寸不爛之舌一樣對你精神喊話，無論是作為醫療或娛樂用途

人類吸食鴉片的歷史已有上千年

Truth be told, they don't actually kill pain, they just make you forget about it

說實話，它們並不能真的鎮痛，它們只是讓你忘記疼痛而已

They relieve suffering by blocking the transmission of pain signals to the brain,

它們靠阻擋大腦接收疼痛信號來緩解疼痛

And then by massaging the brain's opioid receptors to alter its perception of pain,

接著為了轉移大腦對疼痛的感知力，它們使腦內的鴉片類受體放鬆

whispering, "Everything's cool, man. Just relax. Sure, you're bleeding all over the place, but it's no big deal."

悄悄地說：「嘿老兄，一切都很好，放鬆就沒事了！雖然血流得到處都是，但這沒什麼大不了的！」

There are three types of opioids: natural opiates, semi-synthetics, and synthetics.

鴉片分三種：天然鴉片、半合成鴉片及合成鴉片

Natural opiates, like morphine and codein, are derived right from the old Opium Poppy Plant.

天然鴉片，像是嗎啡和可待因，是直接從罌粟植物中提煉出來的

Not a coincidence, by the way, that Dorothy and her friends got all sleepy and chill in that

順帶一提，桃樂絲和她朋友們，在奧茲王國翡翠城外的罌粟園裡變得昏昏欲睡

poppy field outside the Emerald City in Oz.

Morphine is the active ingredient in Opium, and it was first extracted in its purest form

嗎啡是鴉片中的活性成分，首度於19世紀早期從生鴉片(未加工鴉片)中提煉而出

in the early 1800s, to become the most commonly used pain killer during the Civil War

在美國內戰時期成為人們最普遍使用的止痛藥

Before that, fainting ladies sipped Laudanum, or opium diluted in alcohol to calm their nerves.

在那之前，容易頭暈的女性會小酌鴉片酊(鴉片劑)，或用酒精稀釋過的鴉片來舒緩疼痛

So lots of people were enjoying the mellowing effects of Morphine a little too much.

也因為有很多人過度沉溺在這個舒緩效果

So in the 1870s, chemists started working on an alternative, and they came up with a doozy, about

所以在1870年代，化學家開始研究其他替代方案，於是就有了海洛因