The Critical Importance Of Sleep

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Most people who come to see me complaining of fatigue are worried something is wrong with them physically but turn out only to be sleep deprived.  Sleep seems to be something we all wish we did more, making us for the most part a chronically and persistently sleep-deprived society. Though some studies suggest large differences exist in how much sleep different people need to function normally, the range varying from less than 6 to more than 9 hours, and that short sleepers and long sleepers run in families (suggesting a genetic component for people operating on the extremes of the sleep curve), other studies suggest as many as 33% of us don’t get enough sleep to satisfy our basal sleep need (the amount of sleep needed on a nightly basis to perform optimally).

The reasons for this are numerous. Many of us find our best or only time to socialize is late at night. Some find nighttime their only time to relax and unwind, or spend time with their children, or pursue their hobbies. Others are so busy and need to accomplish so much that their daytime work cuts into their nighttime sleep. But unless you make up your accumulated sleep debt (the extra amount of sleep you need to return to normal functioning after being deprived of a normal amount of sleep over time) at some point during the week (commonly accomplished on the weekends), you will find yourself becoming chronically fatigued.

A small amount of sleep debt often makes itself felt initially by a mild to moderate dropping off of energy roughly between 3 and 5 p.m. in the afternoon. But more severe sleep debt, if allowed to accumulate, can have the following detrimental effects:

  1. Weight gain (or a reduced ability to lose weight). This appears to occur via changes in hormone levels, specifically a decrease in serum leptin (a hormone which causes satiety) and an increase in serum ghrelin (a hormone which causes hunger). It should be noted no studies have shown definitively that sleep-deprived patients actually weigh more than non-sleep deprived patients, however.
  2. Chronic severe fatigue.
  3. Irritability.
  4. Decreased ability to concentrate.
  5. Depression. Interestingly, depression can cause fatigue, can be caused by fatigue, and can therefore be confused with fatigue.
  6. Impaired short-term memory.
  7. Decreased libido.
  8. Poor judgment.
  9. Increased risk of car accidents, which can be higher than in people who drive while intoxicated.
  10. Decreased productivity.
  11. Decrease in resistance to viral infections.


In the same way we often only realize the benefit of a medication when it’s stopped and we start to feel worse, just how severely sleep deprivation is impairing our functioning may only become apparent when we improve it. Make a commitment to get the amount of sleep your body tells you that you need—no matter what—and note what, if anything, improves. See how you rate the quality of your life in general when you’re getting adequate sleep compared to when you’re not. The difference may surprise you.

Certainly quality of sleep is as important as quantity, but often is something over which we have less control as it frequently results from a disease like restless leg syndrome or obstructive sleep apnea. If you’re getting what has in the past been for you an adequate amount of sleep but now find yourself chronically fatigued, you should consult your physician to see if something is disordering the quality of your sleep.

Finally, even if you have every intention of sleeping an appropriate number of hours, you may have difficulty doing so. Difficulty falling asleep is often due to churning thoughts, either from anxiety or excitement. Frequent awakenings can be due to anything from nocturia (the need to urinate at night) to depression. Once your doctor has ruled out organic causes, one technique that often helps to induce sleep (whether the difficulty occurs when you first lie down or after you’ve been awakened) is called a paradoxical intervention. Often being unable to fall asleep several nights in a row actually induces performance anxiety, i.e., the expectation that falling asleep will be difficult creates anxiety that actually prevents sleep. People often lie awake for hours struggling to fall asleep, miserable. To use a paradoxical intervention, you would instead lie in bed with the conscious intention to stay awake. If the diagnosis of performance anxiety is correct, it’s astonishing how often paradoxical intervention works.

We should all be merciless about defending our sleep. As a direct primary care physician, I spend much of my time encouraging patients to get adequate sleep. We often think we can sacrifice it temporarily for a variety of reasons—and certainly if we do so infrequently, we won’t likely suffer any adverse effects. The problem comes in when we do so repeatedly, thinking perhaps because initially we don’t suffer any negative consequences that we can continue to function normally with an inadequate amount in the long term. But nothing could be further from the truth. If for no other reason that when we’re well rested we feel more capable of handling the obstacles that invariably arise in life, we should make every effort to conceive of our sleep as a top priority rather than something we just happen to do at the end of the day.

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