In 1965, 17-year-old high school student, Randy Gardner stayed awake for 264 hours. That's 11 days to see how he'd cope without sleep. On the second day, his eyes stopped focusing. Next, he lost the ability to identify objects by touch. By day three, Gardner was moody and uncoordinated. At the end of the experiment, he was struggling to concentrate, had trouble with short-term memory, became paranoid, and started hallucinating. Although Gardner recovered without long-term psychological or physical damage, for others, losing shuteye can result in hormonal imbalance, illness, and, in extreme cases, death.
在1965年，17歲的高中學生Randy Gardner維持了264小時的清醒狀態。累計11天，來看看他是怎麼保持清醒的。第二天，他的眼睛已經無法聚焦了，然後，他失去了依靠觸摸來辨別物體的能力。第三天，Gardner變得喜怒無常，動作也無法協調。
At the end of the experiment, he was struggling to concentrate, had trouble with short-term memory, became paranoid, and started hallucinating. Although Gardner recovered without long-term psychological or physical damage, for others, losing shuteye can result in hormonal imbalance, illness, and, in extreme cases, death.
在實驗結束的時候，保持專注對他來說十分艱難，短期記憶出現了問題，變的易怒，而且出現了幻覺。儘管後來Gardner痊癒了，沒有長期的生理或心理的後遺症，但對於其他人來說失去睡眠可以導致荷爾蒙失衡，生病，在極端情況下甚至會死亡。
We're only beginning to understand why we sleep to begin with, but we do know it's essential. Adults need seven to eight hours of sleep a night, and adolescents need about ten. We grow sleepy due to signals from our body telling our brain we are tired, and signals from the environment telling us it's dark outside.
我們才剛剛開始理解為什麼我們要從睡覺開始，但我們知道這是必要的。成年人每晚需要7到8小時的睡眠，而青少年則需要10小時左右。我們變困是因為身體發出暗示，告訴我們的大腦「我們累了」，環境中的信號告訴我們，外面天黑了。
The rise in sleep-inducing chemicals, like adenosine and melatonin, send us into a light doze that grows deeper, making our breathing and heart rate slow down and our muscles relax. This non-REM sleep is when DNA is repaired and our bodies replenish themselves for the day ahead.
嗜睡化學成分的上升，比如腺苷和褪黑素，使我們進入淺睡眠，並越睡越深，使我們的呼吸和心跳變緩，肌肉變放鬆。DNA在這段非快速眼動睡眠期被修復，我們的身體也及時補充能量以準備迎接新的一天。
In the United States, it's estimated that 30% of adults and 66% of adolescents are regularly sleep-deprived. This isn't just a minor inconvenience. Staying awake can cause serious bodily harm. When we lose sleep, learning, memory, mood, and reaction time are affected. Sleeplessness may also cause inflammation, halluciations, high blood pressure, and it's even been linked to diabetes and obesity.
在美國，大概30%的成人和66%的青少年經常缺少睡眠。這並不只是個小小的不便，長期保持清醒會對身體產生巨大的傷害。當我們失去睡眠的時候，學習，記憶，情緒和反應時間會受到影響。失眠還可能會導致發炎，幻覺，高血壓，它甚至與糖尿病和肥胖有關。
In 2014, a devoted soccer fan died after staying awake for 48 hours to watch the World Cup. While his untimely death was due to a stroke, studies show that chronically sleeping fewer than six hours a night increases stroke risk by four and half times compared to those getting a consistent seven to eight hours of shuteye.
在2014年，一個鐵桿球迷因為連續48小時觀看世界盃而死亡。雖然他是因為中風而「英年早逝」，研究表明，長期維持每日少於六小時的睡眠，相對於那些保持每晚7到8小時睡眠的人來說增加了4.5倍的中風風險。
For a handful of people on the planet who carry a rare inherited genetic mutation, sleeplessness is a daily reality. This condition, known as Fatal Familial Insomnia, places the body in a nightmarish state of wakefulness, forbidding it from entering the sanctuary of sleep. Within months or years, this progressively worsening condition leads to dementia and death.
對於那些世上少數的，通過遺傳得到基因異變的人來說，失眠是家常便飯。這種症狀，被稱為致死性家族失眠症，將身體置於一種噩夢般的清醒狀態，防止患者進入睡眠這個庇護所。在幾個月到幾年內，這種逐漸惡化到病情會導致痴呆和死亡。
How can sleep deprivation cause such immense suffering? Scientists think the answer lies with the accumulation of waste prducts in the brain.
失眠是如何導致如此嚴重的痛苦的？科學家們認為答案是代謝物在大腦中的累積。
During our waking hours, our cells are busy using up our day's energy sources, which get broken down into various byproducts, including adenosine. As adenosine builds up, it increases the urge to sleep, also known as sleep pressure. In fact, caffeine works by blocking adenosine's receptor pathways.
在清醒的時候，我們的細胞緊張的消耗一天的能量，分解成各種副產品，包括腺苷。當腺苷累積起來的時候，它增加了睏倦感，也就是睡眠壓力。事實上，咖啡因是靠阻斷接受腺苷的感知器官來實現其作用的。
Other waste products also build up in the brain, and if they're not cleared away, they collectively overload the brain and are thought to lead to the many negative symptoms of sleep deprivation.
其他的代謝物也會積聚於大腦，如果不清理出去，它們會導致大腦和思想超負荷運轉，並導致各種失眠症狀。
So, what's happening in our brain when we sleep to prevent this? Scientists found something called the glymphatic system, a clean-up mechanism that removes this buildup and is much more active when we're asleep.
那我們睡覺的時候，大腦是如何防止這些發生的呢？科學家們發現了一種叫glymphatic system的腦部淋巴系統，一種能清除這些積聚物的清掃系統，當我們睡覺的時候，這個系統更加活躍。
It works by using cerebrospinal fluid to flush away toxic byproducts that accumulate between cells. Lymphatic vessels, which serve as pathways for immune cells, have recently been discovered in the brain, and they may also play a role in clearing out the brain's daily waste products.
它利用腦脊液來清除在細胞之間的有毒物質。淋巴管，為免疫細胞提供路徑的血管，最近被發現存在於大腦中，淋巴管也可能在清除大腦日常代謝物中扮演了重要的角色。
While scientists continue exploring the restorative mechanisms behind sleep, we can be sure that slipping into slumber is a necessity if we want to maintain our health and our sanity.
雖然科學家們還在繼續探索關於睡眠的修復機制，我們可以肯定，想要保持健和理智，打瞌睡是必需的！