Every time you breathe in, air travels down the trachea, through a series of channels called bronchi, and finally reaches little clusters of air sacs called alveoli. There are some 600 million alveoli in the lungs, adding up to a surface area of roughly 75 square meters— the size of a tennis court. These tiny sacs, only one cell thick, facilitate a crucial exchange: allowing oxygen from the air we breathe into the bloodstream and clearing out carbon dioxide.
每當你吸氣時, 空氣就會向下進入氣管, 通過一連串的通道,即支氣管, 最終抵達一小群 一小群的氣囊,即肺泡。 肺部大約有六億個肺泡, 加總起來的表面積有 約七十五平方公尺—— 等同一個網球場的大小。 這些只有一個細胞厚度的小氣囊 能促進一項重要的交換功能: 讓吸入空氣中的氧氣能進入到血液, 並將二氧化碳清出。
Pneumonia wreaks havoc on this exchange. Pneumonia is an infection of the alveoli that causes them to fill with fluid. There are many different kinds of pathogens that can cause pneumonia. The most common ones are viruses or bacteria.
肺炎會破壞這種交換功能。 肺炎是一種肺泡感染, 會造成肺泡充滿液體。 多種不同的病原體會造成肺炎。 最常見的是病毒或細菌。
These microscopic invaders enter the body via droplets either in the air we breathe, or when we touch our eyes, noses, or mouths after touching a contaminated surface. Then, they face the respiratory tract’s first line defense: the mucociliary escalator. The mucociliary escalator consists of mucus that traps invaders and tiny hairs called cilia that carry the mucus toward the mouth, where it can be coughed out.
這些微小的入侵者進入身體的方式 包括透過吸入空氣中的飛沫, 或者當我們在接觸到 受感染的表面之後 再去觸碰我們的眼睛、鼻子或嘴巴。 接著,這些入侵者要面對 呼吸道的第一道防線: 黏膜纖毛活動梯。 黏膜纖毛活動梯的構成元素 包括會困住入侵者的黏液 及微小毛狀體,纖毛, 它們會把黏液帶向口部, 讓黏液能被咳出。
But some of these invaders may get past the mucociliary escalator into the lungs, where they meet the alveoli. Because alveoli serve as critical exchange points between the blood and air from the outside world, they have their own specialized types of white blood cells, or macrophages, which defend against foreign organisms by enveloping and eating them. When pathogens enter the lungs, the macrophages work to destroy them. The immune system releases additional white blood cells in the alveoli to help. As these immune cells fight the pathogens, they generate inflammation— and fluid as a by-product of the inflammation.
但有些入侵者可能會 通過黏膜纖毛活動梯, 進入肺部,在那裡碰到肺泡。 因為肺泡是來自外在之空氣 與血液之間的重要交換點, 它們擁有自己專門的 白血球細胞,或巨噬細胞, 這些細胞會對抗外來有機體, 將它們包裹住並吞噬掉。 當病原體進入肺部, 巨噬細胞就會盡力將它們摧毀。 免疫系統會在肺泡中釋放出 額外的白血球細胞,伸出援手。 當這些細胞在對抗病原體時, 它們會產生發炎—— 以及發炎的副產物:液體。
When this fluid builds up, it makes gas exchange inside the alveoli much more difficult. As the level of carbon dioxide in the bloodstream begins to rise, the body breathes more quickly to try to clear it out and get more oxygen in. This rapid breathing is one of the most common symptoms of pneumonia. The body also tries to force the fluid out of the alveoli through coughing.
當這些液體逐漸增加,就會讓 肺泡內的氣體交換變得越來越困難。 當血液中的二氧化碳濃度開始上升, 身體就會加速呼吸, 試圖清掉二氧化碳 並讓更多氧氣進來。 這種急促呼吸是肺炎 最常見的症狀之一。 身體也會嘗試透過咳嗽 來將液體逼出肺泡。
Determining the cause of pneumonia can be difficult, but once it is established, doctors can prescribe antibiotics, which may include either antibacterial or antiviral treatments. Treatment with antibiotics helps the body get the infection under control. As the pathogen is cleared out, the body gradually expels or absorbs fluid and dead cells. The worst symptoms typically fade out in about a week, though full recovery may take as long as a month.
肺炎原因的判斷有可能很困難, 但一旦確認了,醫生就能開抗生素, 可能是抗菌劑或是抗病毒的治療。 用抗生素治療 能協助身體將感染控制住。 當病原體被清除, 身體就會漸漸排出或吸收 液體及死亡細胞。 最糟糕的症狀通常 在一週左右就會減緩, 不過完全康復可能要花上一個月。
Otherwise healthy adults can often manage pneumonia at home. But for some groups, pneumonia can be a lot more severe, requiring hospitalization and oxygen, artificial ventilation, or other supportive measures while the body fights the infection. Smoking damages the cilia, making them less able to clear even the normal amount of mucus and secretions, let alone the increased volume associated with pneumonia. Genetic and autoimmune disorders can make someone more susceptible to pathogens that can cause pneumonia. Young children and the elderly also have impaired clearance and weaker immune systems. And if someone has viral pneumonia, their risk of bacterial respiratory infection is higher.
其他情況下都很健康的成人 通常在家休養即可治好肺炎。 但對某些族群而言, 肺炎可能的嚴重許多, 在身體對抗感染期間, 會需要住院及氧氣、 人工呼吸器,或其他 維持生命的措施。 抽菸會損害纖毛, 讓它們甚至不太能清理掉 正常量的黏液和分泌物, 因為肺炎而增加的量就更難處理了。 有基因性和自體免疫疾病的人 更容易受到肺炎病原體的影響。 孩子和長者的清理功能也可能較差, 免疫系統也較弱。 如果得到病毒性肺炎, 細菌性呼吸道感染的風險也會提高。
Many of the deaths from pneumonia are due to lack of access to healthcare. But sometimes, even with appropriate care, the body enters a sustained fight against the infection it can’t maintain, activating inflammatory pathways throughout the body, not just in the lungs. This is actually a protective mechanism, but after too long in this state organs start shutting down, causing shock and sometimes death.
許多肺炎致死的案例 是因為無法取得健康照護。 但有時就算有妥善的照護, 身體對抗感染的抗戰 會變成它無法維持的持久戰, 因而啟動身體各處的發炎傳播途徑, 不僅是在肺部。 這其實是一種保護機制, 但若在這個狀態太久, 器官會開始停止運作, 造成休克,有時甚至造成死亡。
So how can we prevent pneumonia? Eating well and getting enough sleep and exercise helps your body fight off infections. Vaccines can protect against common pneumonia-causing pathogens, while washing your hands regularly helps prevent the spread of these pathogens— and protect those most vulnerable to severe pneumonia.
所以,我們要如何預防肺炎? 吃好、睡足,以及做運動 能幫助你的身體擊退感染。 疫苗能保護你 對抗一般造成肺炎的病原體, 經常洗手能協助你 避免傳播這些病原體—— 保護那些最脆弱的人 不要得到嚴重的肺炎。