Grass growing, flowers blooming, trees growing new leaves,

青草滋長、百花盛開、萬木萌發

but if you get allergies,

但若你患有過敏

this explosion of new life probably inspires more dread than joy.

新生命的蓬勃可能帶來恐懼而非喜悅

Step outside, and within minutes, you're sneezing and congested.

只要走出戶外幾分鐘，你便開始打噴嚏、鼻塞

Your nose is running,

你的鼻水不停

your eyes are swollen and watery,

你的眼睛腫脹泛淚

your throat is itchy.

你的喉嚨搔癢

For you and millions of others, it's seasonal allergy time.

對你和其他數百萬人來說，季節性過敏開場了

So what's behind this onslaught of mucus?

這些猛烈的黏液攻擊為何出現？

The answer lies within you.

答案就藏在你身體中

It's your immune system.

是你的免疫系統

Seasonal allergies, also called hay fever, or allergic rhinitis,

季節性過敏也稱為花粉熱、過敏性鼻炎

are a hypersensitive immune response to something that's not actually harmful.

是一種對於無害物質的免疫過敏反應

Pollen from trees and grass,

草木的花粉

and mold spores from tiny fungi find their way into your mucous membranes

和微小黴菌孢子進入你的黏膜

and your body attacks these innocuous travelers

而後你的身體攻擊這些無害的旅客

the same way it would infectious bacteria.

就像抵抗細菌感染一樣

The immune system has a memory.

免疫系統具有記憶

When a foreign substance gets tagged as threatening,

當外來物質被視為威脅

white blood cells produce customized antibodies

白血球會製造特定的抗體

that will recognize the offender the next time around.

在下次入侵者靠近時將它認出來

They then promptly recruit the body's defense team.

然後迅速召集身體的防衛小隊

But sometimes, the immune system accidentally discriminates

然而，有時免疫系統會意外地排斥

against harmless substances, like pollen.

抗拒無害的物質，如：花粉

When it wafts in again, antibodies on the surface of white blood cells

當它再次飄入，白血球表面的抗體

recognize it and latch on.

會偵測出來並抓住它

This triggers the cell to release inflammatory chemicals,

這會引發細胞釋放發炎化學物質

like histamine,

如組織胺

which stimulate nerve cells,

它會刺激神經細胞

and cause blood vessels in the mucous membranes to swell and leak fluid.

促使黏膜的血管腫脹並滲出液體

In other words, itchiness, sneezing, congestion, and a runny nose.

也就是發癢、打噴嚏、鼻塞跟流鼻水

Allergies usually, but not always, show up for the first time during childhood.

第一次過敏通常(非絕對)在兒時出現

But why do some people get allergies and others don't?

但為何有些人會過敏，其他人不會？

Allergies tend to run in families, so genetics may be one culprit.

過敏有家族罹患的傾向，所以基因可能是罪魁禍首之一

In fact, errors in a gene that helps regulate the immune system

事實上，協助調節免疫系統的基因若有錯誤

are associated with higher rates of allergies.

罹患過敏的機率可能會較高

The environment you grow up in matters, too.

你生長的環境也有關係

Being exposed to an allergen as a baby

在嬰兒時期曝露於過敏原中

makes you less likely to actually develop an allergy to it.

會使你較不易對其產生過敏

People who grow up on farms,

生長於農場、

in big families,

大家族、

and in the developing world also tend to have fewer allergies,

和開發中國家的人也較不易患有過敏

although there are plenty of exceptions, partly thanks to genetics.

雖然有許多例外，部份是由於基因

One theory is that as children,

有種理論是：這些人小時候

they encounter more of the microbes and parasites

接觸較多與傳統捕獵社會共同演化的

that co-evolved with traditional hunter-gatherer societies.

微生物和寄生蟲

Called the hygiene hypothesis,

這理論稱為「衛生假說」

the idea is that when the immune system

概念是：當免疫系統

isn't exposed to the familiar cast of microbes,

沒有曝露在常見的微生物之中

it'll keep itself busy mounting defenses against harmless substances,

系統便會自己忙著對付無害的物質

like pollen.

比如花粉

Another theory is that an immune system toughened up by a barrage of pathogens

另一種理論是：受到病原體猛攻而強化的免疫系統

is less likely to overreact to allergens.

較不容易對過敏原反應過度

Pollen is a common offender, just because we encounter so much of it,

花粉是常見的肇事者，只因為我們大量接觸它

but there's a long list of substances:

但有許多物質：

dust,

灰塵

animal dander,

動物皮屑

insect venom,

昆蟲毒液

medications,

藥物

certain foods,

特定食物

that can send your immune system into overdrive.

都會使你的免疫系統超載

Some of these reactions can be scary.

其中一些反應可能很嚇人

An allergy can develop into full-blown anaphylaxis,

某些過敏會發展成「全身型過敏性反應」

which typically brings on severe swelling,

通常會引起嚴重腫脹

shortness of breath,

呼吸困難

and very low blood pressure.

和極低血壓

It can be deadly.

它可能會致命

The body can even have an allergic reaction to itself

身體甚至會對自己產生過敏反應

causing auto-immune disorders,

導致「自體免疫性疾病」

like multiple sclerosis, lupus, and type 1 diabetes.

如：多發性硬化症、狼瘡和第一型糖尿病

But even non-life threatening allergy symptoms can make you miserable,

但就算是不危及生命的過敏症狀也會令你很悲慘

so what can you do about it?

那你可以怎麼做？

Medications can help reduce the symptoms.

藥物可以幫助減緩症狀

The most common ones keep histamines from binding to your cells.

最常見的藥會避免組織胺與細胞結合

These antihistamines stop the inflammation response.

這些抗組織胺藥物能抑制發炎反應

Steroids can help dial down the immune system.

類固醇能幫助降低免疫系統反應

Another more permanent option is immunotherapy.

另一種較持久的方法是「免疫療法」（減敏治療）

Deliberate, controlled exposure

謹慎地控制對於單一過敏原的曝露

to gradually increasing amounts of an allergen

並逐漸增加劑量

can teach the immune system that it isn't dangerous after all.

能使免疫系統了解它不具危害

And if you're really adventurous, there's a less traditional option:

如果你真的很有冒險精神，有種非正統的選擇：

intestinal parasites.

腸道寄生蟲

When hookworms sink their teeth into the intestinal wall,

當鉤蟲將牙齒嵌入腸壁

they secrete chemicals that blunt the immune system.

牠們會分泌削弱免疫系統的化學物質

Some studies suggest that hookworms can treat allergies,

有些研究顯示鉤蟲可治療過敏

which may be another reason

這可能也就是為什麼

allergies are more common in industrialized countries

在工業化國家中過敏更為常見

where hookworms are few and far between.

因為這些地方較少有鉤蟲

Of course, you can always just wait your seasonal allergies out.

當然，你可以等著季節性過敏消失

The spring pollen onslaught dwindles by mid-summer,

仲夏前，春季花粉的攻擊會減弱

just in time for ragweed season.

正好接上豚草季（另一種過敏原）