Every once in a while you have a bad night's sleep and you know exactly why: You found yourself at the coffee maker at 4 p.m. or there were sirens blaring outside your window all night or maybe your allergies are killing you. But more often than not the reasons behind your less-than-satisfactory slumber remain a mystery and you slog through the day with the unpleasant memory of your alarm clock's siren close at hand.

有时偶尔睡不好觉，你能知道是什么原因：下午4:00喝咖啡了，窗外整夜响着汽笛，或者过敏毛病又犯了。但很多时候，睡眠不好的真正原因都潜伏在暗处，而你却只能在闹钟的轰炸下挣扎面对新的。

We're shining a light on some of the most surprising reasons you can't sleep below. Some of them you can't control, but some of them require only the tiniest of tweaks to help you hit the hay in no time.

下面这些导致睡眠问题的原因可能会让你感到意外，有些你确实无法控制，但有些只要稍作努力就能找回倒头就睡的好睡眠！

1. You Slept In Saturday And Sunday

周末呼呼大睡

We've all been tempted to spend some extra time in bed on a Saturday or Sunday morning (or both, whoops!), but experts say that sleeping late on the weekend (and staying up late, too) can be a bad idea -- for reasons other than productivity. Adjusting your wakeup time can throw off your biological rhythms so drastically that your body feels like it traveled across time zones, and when it comes time to drift off Sunday night, this so-called social jet lag likely won't let you fall asleep without a fight.

谁都难以抗拒周六或周日早上的赖床时光（或者两天都赖床，哈！），但导师表示，周末赖床（熬夜同理）是个坏习惯——除了恢复精力外，毫无益处。改变起床时间会彻底打乱生物钟，使身体仿佛经历了时差，等到周日晚上该睡觉时，所谓的“假后返工时差”就出现了：不经过一通辗转反侧，你是绝不可能睡着的。

2. It's A Full Moon

恰逢满月时刻

No, you're not turning into a werewolf. But the lunar cycle does seem to have some effect on our sleep, at least according to a small study. Researchers found that during the nights around a full moon, people get less deep sleep, less total sleep and took about five extra minutes to fall asleep.

哈，不是说你要变成狼人啊！但根据小众研究，月运周期确实会影响我们的睡眠。研究人员发现，满月时人们的睡眠会变浅变少，入睡也要多花5分钟。

3. Your Room Is Too Cold -- Or Too Hot

房间过冷过热

You might think you know what makes for a cozy bedroom, but there's actual research examining optimal sleeping temperature. Generally, the sweet spot is somewhere between 60 and 67 degrees Fahrenheit, Dr. Christopher Winter wrote in a recent blog for HuffPost, with temps below 54 or above 75 deemed disruptive to your slumber.

你自以为很擅长把卧室整理得舒舒服服，但你知道吗，睡眠温度也很重要呢！克里斯托弗-温特博士在《郝芬顿邮报》的博文上写道：睡眠温度在60-67华氏度（15-19摄氏度），温度低于54华氏度（12摄氏度）或高于75华氏度（23摄氏度）都会妨碍睡眠。

4. You're Not Wearing Socks

没穿睡袜

Even if you've set the thermostat correctly, some people are just disposed to having colder than comfortable extremities. But this can become a problem at bedtime, since warm hands and feet are part of a delicate thermoregulatory dance that seems to predict how quickly you'll fall asleep, according to a 1999 study. Speed up the process by pulling on a pair of clean socks before climbing into bed.

就算你把温度调节到状态，可有人偏偏喜欢偏冷一点的环境。这就造成睡眠问题了。根据1999年一项研究，手脚温暖才能保证体温平衡，进而保证快速入睡。所以上床前可以套一双干净袜子，这样入睡会更快些。

5. It's Too Quiet

太安静了

Yes, you want your sleep sanctuary to be calm and quiet, but complete silence can lead to problems. If your room is too quiet, every little "inconsistency of sound" becomes that much more evident and disruptive, Thomas Roth, Ph.D., director of the Sleep Disorders and Research Center at Henry Ford Hospital in Detroit, told Prevention. A white-noise machine can help!

你希望有个安静的睡眠环境无可厚非，可是，安静也容易引发诸多问题。托马斯-罗斯是底特律市亨利福特医院睡眠障碍与研究中心的主任，他告诉《预防》杂志说：如果卧室太安静，哪怕是稍微不协调的声音都会显得特明显特烦人。那样的话，你得用白噪音机器了！

6. You're Afraid Of The Dark

害怕黑暗

You may be too proud to admit it (even to yourself), but try to be completely honest for a minute: Are you afraid of the dark? Fear of the dark could actually be messing with your shut-eye. In research presented at the 2012 SLEEP conference, people who reported themselves to be "bad sleepers" were found to get more anxious and more easily startled by noises once the lights went off than people who considered themselves "good sleepers", MSN reported. The researchers posited that bedtime anxiety that's often chalked up to knowing a night of fitful sleep awaits may actually be due to a legitimate and untreated phobia.

或许你自尊心太强，不愿承认自己怕黑（哪怕是对自己），但还是请试试完全坦诚吧：你害怕黑暗吗？怕黑其实也会影响睡眠。MSN报导，根据2012年睡眠大会的研究，关灯之后，自称“睡眠差”的人比睡眠好的人更容易紧张不安。研究人员推测，表现为整夜不时辗转反侧的“睡前焦虑”很可能是因为这种合乎常理而又未经调整的恐惧心理造成的。

7. You're Exhausted

你已筋疲力尽

It's been a long day (or week) and you're feeling stretched to your limits. All you want to do is get into your bed, and you practically have to drag yourself into it. But despite that overwhelming exhaustion, you find yourself annoyed while counting sheep. What gives? "There's actually a big difference between being exhausted and being sleepy," Roth told WebMD. Your body is still on high-alert, even though you can hardly carry on, whether it's because of stress or physical activity. Long story short, rushing to bed doesn't equate to rushing to sleep. No matter how exhausted you feel, it's a good idea to wind down calmly and quietly first.

今天（这周）都快累趴下了，你拖着笨重的身体倒在床上，只想赶快补觉。可是，虽然身体早已疲惫不堪，你却发现自己竟然睡不着！这是咋了？罗斯告诉WebMD：“疲惫和困倦有很大区别。虽然你很累，但身体因为压力或运动还处于高度紧张状态。” 简而言之，扑倒在床并不等于立马就能入睡。所以，不管你有多累，也要先让情绪放松平静下来。

8. You Share A Bed

身边有睡伴

We know, we know -- you love to snuggle. But allowing a pet in the bed is asking for trouble falling asleep. Every time Fluffy makes a move or a sound, you'll toss and turn right along with her, not to mention she drags with her allergy-triggering animal dander that you're better off keeping outside the bedroom.

我们懂的，你喜欢睡觉时有个依靠。可是，让宠物上床并不利于睡眠。每次宠物翻身或发出声音，你也得顺着它跟着翻身，更别提床上可能沾满了容易引人过敏的动物皮屑了！所以，还是别让宠物进卧室吧。

And it's not just furry friends that cause problems. Sharing a bed with a partner who tosses and turns or kicks or snores can give you just as much trouble falling asleep. One study found that when sharing a bed, couples experience 50 percent more sleep disturbances than when sleeping solo, the BBC reported. Separate beds may be catching on -- a recent report from Toronto found that 30 to 40 percent of couples sleep apart.

当然，不只是宠物会带来问题。如果伴侣睡觉总是翻来动去或打呼噜，那也真够闹心。BBC报导，调查显示，同床共寝竟然会使睡眠障碍提升50%！现在“分床睡觉”已经变得越来越流行——多伦多一则报道说，30-40%的夫妇选择分开睡觉。