A negative. What? It’s way more important, what if I need a blood transfusion?

A型陰性。怎樣？這很重要欸，萬一我需要輸血怎麼辦？

Hey blood brothers and sisters, Julian here for DNews from the youtube space in LA

嘿，各位如親兄弟姐妹的觀眾，我是《DNews》的 Julian

Even if you don’t know your blood type you’ve probably heard the terms thrown around before.

就算你不知道自己的血型是什麼，你應該也聽過這些名詞吧

AB positive. O negative. What do they mean?

AB 型陽性。O 型陰性。這是什麼意思啊？

It turns out there are actually 33 different systems for categorizing a person’s blood,

原來，有多達 33 種不同的系統來分類人類的血型

but the nomenclature you’re most familiar with is a combination of two of them;

但你最熟悉的術語，應該是其中兩個的綜合

the ABO system and the Rh system.

ABO 血型系統和 Rh 血型系統

The reason these two are so much more well known is because they are by and large the

讓這兩個血型系統這麼有名的原因，總體來說，是由於

most important factors in blood transfusions. In most cases these alone should be enough

他們是輸血時非常重要的因素。絕大多數的情況下，只要這有兩個因素，就足以

for a doctor to know what kind of blood to pump back into you if you’ve sprung a leak.

讓醫生判斷，你失血時，應該要注回哪種血

It’s why some racing drivers in the ‘70s and ‘80s had their blood type sewn on their race suit

這也是為什麼有些70、80年代的賽車手，會將他們的血型縫在比賽服上

or painted on their car. Nowadays they don’t bother; the tests to determine blood types and compatibility with donor blood

或者漆在車上。現在不用這麼麻煩了；血型和捐贈血相容性的檢驗

are quick and much more foolproof than relying on embroidery or a sticker.

比靠刺繡和貼紙來的快又簡單

So what do the letters and plus/minus symbols actually denote?

所以，那些字母和正／負記號表示什麼意思呢？

They’re describing little surface markers on the blood cells called antibody generators, or antigens for short.

他們是在描述血球細胞表面的小標誌，稱之為抗體產生器，簡稱抗原

Antigens come in a lot of different varieties and your body’s immune system attacks cells

抗原有超級多種類，身體的免疫系統會攻擊

with antigens that don’t match your own. Having the right antigens is like knowing

抗原與自身不符的細胞。細胞上有正確的抗原，就像知道

the password to get into the super secret, boys-only treehouse.

男孩專屬、超機密樹屋的通關密碼

Antigens can be either proteins or sugars. The antigens described by the ABO blood group system

抗原可以是糖類或蛋白質。ABO 血型系統所描述的抗原

are sugars and they come in 4 different combinations or “types”.

是糖類，而且它們有四種不同的組合，或「類型」

Type O means the blood cells have no A or B antigens, so it might be easier to think of it as type Zero.

O 型表示血球細胞沒有 A 或 B 抗原，所以滿容易讓人把它想成是「０」型

People with this blood type can only receive type O because their immune systems

這種血型的人，只能接受 O 型的血液，因為他們的免疫系統

will attack anything with an A or B antigen. But any other blood type can accept type O blood

會攻擊任何有 A 或 B 抗原的細胞。但其他血型的人都能接受 O 型血

because the red blood cells will be ignored by the immune system.

因為紅血球會被免疫系統忽視

Type A means cells have the A antigen so they can’t receive type B blood,

A 型表示細胞有 A 抗原，所以他們不能接受 B 型血，而 B 型表示

and type B means cells have the B antigen and won’t be compatible with type A blood. I think you see where this is going:

細胞有 B 抗原，與 A 型血不相容。我想你應該知道些下來會是怎麼樣：

type AB means the red blood cells have both A and B antigens,

AB 型意味著紅血球同時有 A 和 B 兩種抗原

and so none of the white blood cells will attack anything with A or B antigens.

所以白血球不會去攻擊任何有 A 或 B 抗原的東西

People with this blood type can accept any all human blood. Well, so long as the Rh antigens are correct too.

這種血型的人，可以接受任何人的血液。呃…只要 Rh 抗原也對的話

The Rh blood group system is so named because 75 years ago it was discovered the antigens behaved

Rh 血型系統之所以這麼命名，是由於 75 年前，發現人類抗原的表現

similarly to those in Rhesus macaques. But they are different,

和恆河猴（rhesus macaque）的類似。但它們其實還是不同的

so don’t go around injecting monkey blood all willy-nilly. Rh antigens are proteins, there are 49 varieties

所以不要錯把猴子血拿來注射。Rh 抗原為蛋白質，有 49 種

but one in particular, RhD, is highly immunogenic, meaning immune systems that don’t have it

而特別是其中一種，RhD，非常容易產生免疫反應，也就是說，沒有 RhD 抗原的免疫系統

freak out when they encounter it. So if you have RhD, your blood type has a plus symbol next to it

遇到它時，免疫系統就會很激動。所以如果你有 RhD，你的血型旁邊就會有一個正記號

and you can only donate to other positive blood types, but you can accept positive

你只能捐血給其他陽性血型的人，但你可以些受陽性

and negative blood types. Put the two together and it means O- is the universal donor,

以及陰性血型。把這兩種系統合併使用的話，意味著 O 型陰性是萬能的捐獻者

while AB+ will be the universal receiver.

而 AB 陽性是萬能的接收者

Blood types are passed down through your genes. You can change blood type, but it’s extremely rare.

血型由基因遺傳下來。只有在極其少數的機會下，能變換血型

It either happens from some sort of illness, or if you get a bone marrow transplant

要不是發生某種疾病，不然就是骨髓移殖

your blood will eventually convert to your donor’s type.

血型最後會變成捐贈者的血型

So now you know! Unless you have some rare blood type that needs one of the other 31 blood group systems to describe it,

現在了解了吧！除非你有某種罕見的血型，需要用到任一其他的 31 種血型系統來描述

you now understand what the letters and symbols of your blood type mean.

不然，你現在應該了解自己血型的字母和符號的意思了

In some places like Japan it’s believed that blood types also correspond to personality traits,

有些地方，像是日本，人們相信血型還和人格特徵相呼應

but really it only affects your immune system. Thinking Type O blood makes a person confident and controlled

但其實血型真的只會影響你的免疫系統啦。認為 O 型的人自信又自律

is kind of like thinking Jupiter is going to affect your luck today.

就有點像認為木星會影響你的今日運勢

Speaking of, here’s Laci talking about why Astrology is silly.

談到這個，這邊有個影片是 Laci 談談為什麼占星學很蠢

Check the description for a link if you’re on your mobile.

手機用戶可以參考描述處的連結

Are there any other things like blood types you take for granted because you just never thought about it?

還有其他有關血型你從未想過、覺得理所當然的事情嗎？

If you want us to to explain them, go ahead and ask us in the comments,

如果你想聽我們說明，去留言處發問吧

it’s what we’re here for. I’ll see you next time on DNews.

這是我們存在的用意。下次我們《DNews》見