Feeling tired or fatigued is a common experience. Yet health-care providers often dismiss complaints about tiredness - both because the symptom is universal and because it can be challenging to evaluate medically, says Michael Grandner, director of the University of Arizona's Sleep & Health Research Program in Tucson.

感觉疲惫和精疲力竭是很平常的体验。然而医疗服务人员通常忽略关于疲劳的抱怨，既是因为这种症状很普遍，也是因为在医疗上对此进行评估很有挑战性，迈克尔·格兰德纳(Michael Grandner)，亚利桑那州立大学图森的睡眠及健康研究项目主任说道。

And while tiredness is often temporary, treatable or nothing to worry about, experts say that tiredness that suddenly worsens or prevents you from doing what you want can be a sign of a health problem or sleep disorder.

虽然疲劳通常是短暂的、可治疗的、无需担忧的，专家表示，如果疲劳突然恶化，或者阻止你做你想做的事情，那可能表明你有健康问题或者睡眠障碍。

"Sleep seems to be a canary in the coal mine, where it's sensitive to all these things going on in your body," Grandner says.

格兰德纳说，“睡眠就像煤矿中的金丝雀，在矿里它对你身体中进行的一切活动都很敏感。”

"So, when it starts changing, you want to ask, 'Well, what's going on?'"

“因此，发生改变时，你就会问，‘额，发生什么事了?’”

Sleepiness, fatigue, tiredness: in conversation, people use the terms interchangeably. But medically, their definitions differ. Understanding the differences is an important first step toward tackling the problem - or figuring out if there is one.

困倦、厌倦和疲倦：说话的时候，人们会把这几个词混用。然而在医学上，它们的定义不同。理解这些不同之处是解决问题或者弄明白到底有没有问题的第一步。

Sleepiness is a need for sleep that makes it difficult to stay awake, even while driving, working or watching a movie, and even after ingesting caffeine.

困倦是一种睡眠需求。即使在驾驶、工作、看电影时，甚至摄入咖啡因后，困倦都让人难以保持清醒。

Fatigue, on the other hand, is a deeper sort of an inability, either physical or mental, to do what you want to do, such as get to the grocery store.

而在另一方面，厌倦是一种更深层次的无能，这种无能既是身体上的，也是精神上的，让你没办法做想做的事，比如说去杂货店。

Somewhere in the middle is tiredness, a desire to rest that is less debilitating than fatigue and less dramatic than sleepiness. You can still be productive while tired.

而介于两者之间的是疲倦，一种想要休息的愿望。疲倦不像厌倦那样让人感觉无能，也不像困倦那样来得突然。人疲倦的时候也可以很高产。

Whatever you call it, it's common. In a 2014 survey by the nonprofit National Sleep Foundation, 45 percent of adults said they had been affected by poor sleep or not enough sleep in the previous week.

不管你叫这种症状什么，这都很常见。非盈利机构美国国家睡眠基金会2014年的一项调查显示，45%的成年人说他们在前一周因睡眠质量不好或者睡眠时间不够受到影响。

As many as 20 percent of people report excessive sleepiness on a regular basis. And, a National Safety Council survey reported in 2017 that 76 percent of people felt tired at work.

高达20%的人经常过度困倦。另外，美国国家安全委员会2017年的一项调查显示，76%的人在工作时感到疲倦。