Many adults may think they are getting enough shut⁃eye，but in a major sleep study almost 80 percent of respondents admitted to not getting their prescribed amount of nightly rest. So，what exactly is the right amount of sleep? Research shows that adults need an average of seven to nine hours of sleep a night for optimal functionality. Read on to see just how much of an impact moderate sleep deprivation can have on your mind and body.

许多成年人可能认为自己睡得足够多，但在一项大型睡眠研究中，近80%的受访者承认自己没有达到规定的夜间休息时间。那么，到底睡多久才算合适呢？研究表明，成年人每晚平均需要七到九个小时的睡眠才能达到最佳状态。接下来，我们一起来了解一下，适度缺乏睡眠会对你的身心产生多大的影响。

By getting less than six hours of sleep a night，you could be putting yourself at risk of high blood pressure. When you sleep，your heart gets a break and is able to slow down for a significant period of time. But cutting back on sleep means your heart has to work overtime without its allotted break. In constantly doing so，your body must accommodate to its new conditions and elevate your overall daily blood pressure. And the heart isn't the only organ that is overtaxed by a lack of sleeps. The less sleep you get，the less time the brain has to regulate stress hormones，and over time，sleep deprivation could permanently hinder the brain's ability to regulate these hormones，leading to elevated blood pressure.

每晚睡眠不足六小时，你可能会面临高血压的风险。当你睡觉时，你的心脏会暂时休息，能够减缓跳动一段时间。但是，减少睡眠时间意味着你的心脏必须在没有规定的休息时间的情况下加班工作。长此以往，你的身体必须适应新的状况，并提高你每天的整体血压。而且，心脏并不是唯一因睡眠不足而过度劳累的器官。你睡得越少，大脑调节应激激素的时间就越少，久而久之，睡眠不足可能会永久性地阻碍大脑调节这些激素的能力，从而导致血压升高。

We all hang around in bed during our bouts of illness. But did you know that skipping out on the bed rest can increase your risk of getting sick? Prolonged sleep deprivation has long been associated with diminished immune functions，but researchers have also found a direct correlation between“ modest ” sleep deprivation — less than six hours — and reduced immune response. So try to toughen up your immune system by getting at least seven hours of sleep a night，and maintaining a healthy diet. You'll be glad you got that extra hour of sleep the next time that bug comes around and leaves everyone else bedridden with a fever for three days.

我们生病时都喜欢躺在床上休养。但是，你知道吗？不卧床休息会增加你生病的几率。长期睡眠不足一直与免疫功能下降有关，但研究人员也发现“适度”睡眠不足——少于六小时——与免疫反应降低之间存在直接联系。因此，为了增强你的免疫系统，尽量每晚至少睡七个小时，并保持健康的饮食。下次病毒来袭，其他人因发烧而卧床不起三天时，你就会庆幸自己多睡了一个小时。

During deep REM sleep，your muscles（ except those in the eyes）are essentially immobilized in order to keep you from acting out on your dreams. Unfortunately，this effort your body makes to keep you safe while dreaming can sometimes backfire，resulting in sleep paralysis. Sleep paralysis occurs when the brain is aroused from its REM cycle，but the body remains in its immobilizing state. This can be quite a frightening sensation because，while your mind is slowly regaining consciousness，it has nocontrol over your body，leaving some with a feeling of powerlessness，fear and panic. Most people experience this eerie phenomena at least once in their lives，but those who are sleep deprived are more likely to have panicked episodes of sleep paralysis that are usually accompanied by hallucinations，as well.

在深度REM睡眠期间，你的肌肉（眼睛周围的肌肉除外）基本上处于瘫痪状态，以防你因梦境而行动。不幸的是，这种身体在做梦时为了保护你而做出的努力有时会适得其反，导致睡眠瘫痪。睡眠瘫痪发生在大脑从REM睡眠周期中苏醒，但身体仍处于瘫痪状态时。这可能会让人感到非常害怕，因为在你的大脑慢慢恢复意识时，它无法控制你的身体，让一些人感到无能为力、恐惧和恐慌。大多数人一生中至少会经历一次这种诡异的现象，但那些睡眠不足的人更容易出现伴随幻觉的恐慌性睡眠瘫痪。

想象一下，你的所有记忆都被抹去了；每一个生日、暑假，甚至昨天下午你所做的事情都完全消失了，因为你一点都想不起来了。这个想法令人毛骨悚然，但是没有睡眠的生活就是这样的。睡眠对于大脑的认知功能至关重要，如果没有睡眠，我们巩固记忆、学习日常任务和做决策的能力将会受到很大影响。研究表明，快速眼动睡眠，即梦眠，有助于巩固大脑在一整天中形成的“脆弱”记忆，使它们能够被轻松组织和存储在大脑的长期缓存中。