Why Is Sleep Important?
Many people are unaware of how essential it is to get a good night’s sleep on a regular basis. When work or school deadlines arise, many consider staying up late or “pulling an all-nighter” an efficient way to get everything done. However, studies show that this is the worst thing you can do—skimping on sleep can cause concentration problems, drowsiness, and irritable moods that affect the way your work is delivered the next day. For example, a student may decide to drink coffee and stay up all night to “cram” for a test. While this approach may offer more hours for studying, the detrimental effects of sleep deprivation will likely impair her performance on the test the next day.
Short-term health impact
Sleep is such an important part of our lives that its effects show up quickly when we don’t get enough of it. Getting too little sleep for just one night can:
- Increase stress. Researchers examined two groups of healthy young adults who had to perform an impromptu speech and complete a test that measured reaction times to colors and words. The catch? One group was allowed to sleep the night before, while the other had to stay awake all night long. The sleep-deprived group experienced more severe stress in the face of these fairly simple tasks and exhibited increased blood pressure.
- Disturb mood. Anyone who has felt irritable after a poor night’s sleep understands the profound the connection between sleep and mood. Research shows that sleep-deprived people have a much stronger tendency to classify neutral images—such as pictures of ordinary household objects—as “negative,” whereas people who slept the night before labeled them “neutral.” So even minor annoyances can suddenly seem more menacing or unmanageable after skipping or shortening a night of sleep.
- Impair ability to concentrate. A review of 70 studies on the effects of sleep deprivation found that the most largely affected area was simple attention. For example, sleep-deprived subjects who were asked to press a button each time they saw a light flash had trouble focusing and missed more of the light flashes than their well-rested counterparts. Simple attention is a vital skill that helps us stay safe—imagine how your reaction time to stoplights or traffic hazards would be impaired if you didn’t get enough sleep.
Long-term health impact
Some people might say that it’s a fair trade-off to skimp on sleep now and then, saying that a day or two of tiredness and crankiness is worth the extra time they earned. But while returning to a regular sleeping pattern can restore the negative short-term effects of one night of poor sleep, the long-term consequences of regular sleep deprivation that arise under the surface are much more dangerous. Long-term effects of poor sleep include:
- Heightened risk factor for diabetes. Too much sleep can be as bad for you as too little: people who regularly get less than 6 or more than 9 hours of sleep each night are both faced with an increased risk for type 2 diabetes.
- Increased risk for breast cancer. A survey of breast-cancer patients found a strong association between shorter sleep patterns and recurrence of tumors. This suggests that women who don’t sleep enough each night (less than 6 hours) have an increased risk for more aggressive cancer.
- High blood pressure. There is also strong link between short sleep duration and hypertension, as well as a connection (though not as significant) between too much sleep and hypertension.
- Decreased immune function. According to the Mayo Clinic, people who don’t sleep enough each night get less protection from flu vaccines and are more likely to catch the common cold.
- Major depression. Insomniacs and others who don’t get adequate sleep each night are ten times as likely to develop major depression as those who sleep through the night. Because depression also has a negative effect on sleep patterns, this can create a cycle that is hard to break.
- Obesity. The rising rate of obesity seems to parallel American’s tendency to sleep less than ever before, prompting a Harvard study to investigate. The results were surprising—brain scans of sleepy adults showed that they were less likely to distinguish between high-calorie and low-calorie foods; the part of the brain that inhibits and controls emotions and behavior was not active. This can lead to overeating and making poor food choices in general, which contributes to obesity. Other studies have found that lack of sleep may affect hormones that tell you when you are full—this causes you to overeat when you’re sleepy.
Impact on relationships
The consequences of poor sleep extend far beyond personal health—they can also affect our interactions with others. At the 2013 Society for Personality and Social Psychology (SPSP) annual meeting, scientists from UC Berkeley presented new research suggesting that inadequate sleep can impair our ability to appreciate our partners and loved ones, which can lead to stress and tension in the relationship. The SPSP reports that less sleep means fewer feelings of gratitude and higher levels of selfishness, both of which can make a partner feel unacknowledged and underappreciated.
Financial and economic impact
On a broader scale, poor sleep can have costly and often tragic consequences for society.
- The U.S. Department of Health & Human Services estimates that chronic sleepiness has cost the nation $16 billion in healthcare expenses each year.
- The same study found that poor sleep costs an estimated $50 billion in lost productivity annually.
- Insomniacs lose 11.3 days of productivity a year, costing companies $2,280 per person.
- According to the National Highway Traffic Safety Administration, drowsy driving causes 100,000 car crashes each year, costing about $12.5 million dollars annually.
Check out this infographic, created by Happify, to learn other ways that sleep affects wellbeing.