How does asthma work? - Christopher E. Gaw

譯者: 培婷 黃 審譯者: Yamei Huang

It starts with a cough,

一開始會咳嗽

or a wheeze.

或是喘鳴聲

接著，你感到胸悶

Soon, your chest feels tight.

Your breathing speeds up and gets shallower,

呼吸速度變快，且呼吸變淺

making you feel short of breath.

這讓你感到喘不過氣

These are common symptoms of an asthma attack.

這些是氣喘發作時的典型症狀

全世界有超過 3 億人患有氣喘

Around the world, more than 300 million people suffer from asthma,

and around 250,000 people die from it each year.

每年約 25 萬人因此去世

But why do people get asthma and how can this disease be deadly?

為什麼人們會患有氣喘？ 它又為何如何致命？

Asthma affects the respiratory system,

氣喘影響我們的呼吸系統

particularly the smaller airways,

特別是較細小的氣道

such as the bronchi and bronchioles.

如支氣管和細支氣管

These airways have an inner lining called the mucosa

這些氣道內壁有一層黏膜

that's surrounded by a layer of smooth muscle.

它們被一層平滑肌所包圍

In people with asthma, the airways are chronically inflamed,

氣喘患者的氣道因長期發炎

which can make them hyper-responsive to certain triggers.

這使他們對某些誘發因子高度敏感

Some of the many asthma triggers include tobacco smoke,

這些誘發因子包括香菸味

pollen,

花粉

dust,

灰塵

fragrances,

香水味

exercise,

運動

cold weather,

寒冷天氣

stress,

壓力

and even the common cold.

甚至是普通感冒

When people with asthma are exposed to these triggers,

當氣喘患者接觸這些因子

an asthma attack, or exacerbation, can occur.

會造成氣喘發作或是惡化

But how exactly do such everyday factors lead to an asthma attack?

但這些日常因素 如何導致氣喘發作呢？

If an asthmatic is exposed to a trigger,

當氣喘患者接觸到誘發因子時

the smooth rings of muscle that circle the small airways in their lungs

肺裡包圍著小氣道的平滑肌

contract and become narrow.

會開始收縮，變得更加狹窄

Simultaneously, the trigger worsens inflammation,

同時，誘發因子會加劇發炎

causing the mucosal lining to become more swollen

氣道黏膜變得更加腫脹

and secrete more mucus.

分泌更多黏液

Under normal conditions,

在一般情況下

the body uses this mucus to trap and clear particles, like pollen or dust,

黏液可用來捕捉或清除小顆粒

例如花粉和灰塵

but during an asthma attack,

但是氣喘發作時

it blocks the narrowed airways, making it even harder to breathe.

它會堵住狹窄的氣道 使得呼吸變得更加困難

These effects lead to this symptoms of asthma.

這就導致了氣喘發作時的症狀

Smooth muscle constriction results in the feeling of chest tightness.

平滑肌收縮會導致胸悶的感覺

Excess mucus and increased inflammation can cause coughing.

過多的黏液和惡化的炎症會導致咳嗽

And the wheezing noise?

以及常伴有的喘息聲

That happens because as the airways constrict,

是隨著氣道的收縮

air whistles as it passes through the narrowed space.

空氣經過狹窄空間時所發出的聲音

These symptoms may make a person feel like they're running out of air.

這些症狀會讓人喘不過氣

Yet counterintuitively, during an asthma attack,

不過與直覺相反，氣喘發作時

the inflammation can make it harder to exhale than inhale.

發炎症狀會讓呼氣變得比吸氣更困難

Over time, this leads to an excess of air in the lungs,

久而久之，會導致肺裡的空氣過量

a phenomenon known as hyperinflation.

這現象稱為過度充氣

The trapping of air inside the lungs forces the body to work harder

肺裡的大量空氣會迫使身體

更努力吸氣和吐氣

to move air in and out of them.

Over time, this can lead to reduced oxygen delivery to the body's organs and tissues.

久而久之，這會導致輸送到 身體各器官和組織的氧氣變少

Sometimes, in untreated severe asthma attacks,

有時候，嚴重的氣喘 在來不及治療的情況下

the body can't keep up,

身體無法繼續維持運作

which can lead to death from lack of oxygen.

最終導致缺氧死亡

因此，要如何預防令人不適 且有潛在生命威脅的氣喘發作呢？

So how do we prevent these uncomfortable and potentially fatal attacks

in people who have asthma?

特別是氣喘患者

One way is to reduce the presence of triggers.

方法之一是減少接觸誘發因子

Unfortunately, the world is an unpredictable place

可惜的是，我們無法預知生活的世界

and exposure to triggers can't always be controlled.

也不可能一直不接觸到誘因

This is where inhalers, the primary treatment for asthma, come in.

這時就需要吸入器的幫助 它就是治療氣喘的主要方法

These medications help asthmatics both control and prevent their asthma symptoms.

這種藥物幫助氣喘患者 控制和預防氣喘發作

Inhalers transport medication along the affected airways

吸入器將藥物運送到受侵襲的氣道

using a liquid mist or fine powder to treat the problem at its source.

利用液體噴霧或細粉 從根本上去解決問題

They come in two forms.

吸入器有兩種：

There are reliever medications,

一種是緩解性藥物

which treat symptoms immediately and contain beta-agonists.

它可以直接緩解症狀 並含有乙型受體素

Beta-agonists relax constricted muslces,

乙型受體素可以使緊張的肌肉放鬆

allowing the airways to widen so more air can travel into and out of the lungs.

讓氣道變得通暢 更多的空氣能出入肺部

另一種吸入器則是預防性藥物

The other form of inhalers serve as preventive medications,

which treat asthma symptoms over the long term,

可以達到長期治療氣喘的作用

and contain corticosteroids.

它包含皮質類固醇

Corticosteroids reduce airway sensitivity and inflammation,

皮質類固醇可以減輕 氣道的敏感性和發炎症狀

so asthma can be kept under control.

從而使氣喘得以控制

They're also crucial in preventing long-term damage

這在預防慢性炎症所帶來的

長期傷害方面也有重要作用

from chronic inflammation,

which can cause scarring of the airways.

因為慢性炎症會導致肺部瘢痕形成

Inhalers are known to be very effective,

吸入器是非常有效的

它幫助不少人可以生活得更好

and have helped many people live better lives.

Although we've come a long way in improving how we treat

雖然我們花了很長時間

在改進氣喘的診斷和治療

and diagnose asthma,

we still don't know its exact causes.

我們仍無法確定其明確的發病原因

We currently believe that a combination of genetic and environmental factors

目前我們知道基因和環境因素

會共同導致氣喘發作

play a role,

potentially acting during early childhood.

並且在幼兒時期就有潛在影響

Recent research has even linked poverty to asthma incidents.

最近的研究甚至發現 氣喘和貧窮的關聯

This may be due to reasons ranging

其原因可能是

from exposure to additional pollutants and environmental irritants

過量接觸汙染物和環境刺激

to difficulties in obtaining medical care or treatment.

以及難以獲得醫療治療

As our understanding of asthma improves,

隨著我們更加了解氣喘

we can continue to find better ways to keep people's airways happy and healthy.

我們可以找到讓氣道 舒適及健康的更好方式