Why Do We Feel Tired After A Good Night's Sleep?

03/16/2015 08:04 am ET | Updated Mar 16, 2015
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The question: On several occasions, I've woken up from a "good" night's sleep and still felt surprisingly tired and lethargic. What gives? Why can't I seem to get going after giving my body the uninterrupted rest I know it needs?

The answer: While there are several possible explanations for this unappreciated feeling of cloudiness, Michael Decker, Ph.D., a sleep specialist and associate professor at Case Western School of Nursing, first suggests that something called sleep inertia may be to blame.

"As we sleep, our brain rotates through several stages known as non-rapid eye movement (NREM), slow wave sleep (SWS) and rapid eye movement (REM) sleep," Decker told The Huffington Post. "Although asleep, our brain is metabolically very active in REM sleep, and fairly active in NREM sleep. In the morning, we typically awaken from NREM sleep. As our brain is already metabolically active, the leap to consciousness is very short."

However, when we are still in SWS, the brain reduces metabolic activity, which significantly limits our conscious awareness and responsiveness, according to Decker. If we happen to be in SWS when the alarm clock goes off, the leap to consciousness is a more disruptive one than experienced from NREM or REM sleep.

"The term 'sleep inertia' describes that period of time in which our brain is struggling to engage its wake-maintaining areas, its cognitive and decision making areas, as well as motor function areas," said Decker. This transition can take as little as one hour -- and as long as four hours -- to occur.

Beyond the science of sleep inertia, this morning sluggishness could also be attributed to a variety of sleep disorders, said Decker. From sleep apnea to periodic limb movement disorder, people may struggle with a sleep disorder and not necessarily realize it. These conditions disrupt the continuity and quality of sleep, further exacerbating those feelings of sleepiness even after logging eight hours of shut-eye.

One final culprit could be the furry friend curled up at the foot of the bed, Decker said. We know you love them, but your pets' mid-night movements can disrupt your sleep, and their 5 a.m. wake-up calls for a bathroom break are surely less than helpful. The more they wake you up during the night, the more you should expect that groggy feeling to linger throughout the morning.

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Also on HuffPost:

  • 1 E-readers
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    As if there weren’t enough things keeping you tossing and turning each night, here’s a new one: Using short-wave, blue light-emitting e-readers, like the iPad, iPhone, Nook Color, Kindle and Kindle Fire, before bedtime can make it harder to fall asleep, according to a December 2014 study at Brigham and Women’s Hospital.

    "When blue light hits the optic nerve, it tells the brain to stop producing melatonin," which is "the key that starts the engine for sleep," says Michael Breus, Ph.D., diplomate of the American Board of Sleep Medicine and fellow of the American Academy of Sleep Medicine. "This is especially problematic, since as you get older, the ability to produce melatonin becomes even more compromised."

    Fixes: Open up a real book instead. (Remember those?) If giving up your e-reader is impossible, look for screens and glasses that can block the sleep-stealing blue light on websites like
  • 2 Being overweight
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    Carry extra pounds, especially in the neck and trunk section, and it’s more likely you’ll suffer from sleep apnea, which causes your airway to become blocked or obstructed during sleep, robbing you of quality deep sleep. The condition affects 90 percent of obese men, though it's not purely a man's disease. The Cleveland Clinic reports that after menopause, it’s just as likely to affect women. Even more disturbing, it goes undiagnosed in as many as 80 percent of those who get a lousy night’s sleep.

    "Sleep apnea can mask itself as fatigue, trouble with concentration, dry mouth or even depression," states Dr. Breus. Unfortunately, sleep apnea and obesity is a bit of a chicken-egg scenario. Do sufferers have problems because they’re obese, or is their obesity stoked by their compromised sleep? No one knows for sure, but what’s known is this: Poor sleep makes people less motivated to increase physical activity, which can lead to more weight gain. Additionally, reduced sleep is associated with elevated levels of the hormone leptin, which helps regulate appetite.

    Fixes: Among the various treatments for sleep apnea is a continuous positive airway pressure (CPAP) machine, which delivers air pressure via a mask that sits over your nose or mouth while you sleep. Other treatment options include losing weight, oral appliances (that resemble mouthguards), and Inspire Upper Airway Stimulation (USA) therapy, a new FDA-approved implantable device.
  • 3 Medications
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    Many popular over-the-counter pain medications, like Excedrin and Bayer Back and Body, may contain caffeine, which helps the medication get absorbed more quickly, but can cut into your sleep, according to Dr. Breus (who suggests always checking the label first). If you’re feeling under the weather, beware of nasal decongestants and daytime cold or flu medicines, as well, which can contain pseudoephedrine; you’ll feel jittery instead of tired. Instead, The National Sleep Foundation suggests choosing a medication specifically for nighttime use, like Benadryl, NyQuil or Zyrtec, which usually contain antihistamines that promote drowsiness instead.

    Diuretics, water pills for heart disease and high blood pressure, and ADD medications like Adderall and Ritalin can also disrupt sleep, says Hrayr Attarian, M.D., a neurologist at Northwestern Memorial Hospital in Chicago, Illinois. Other culprits include steroids and some medications for depression or asthma. "As with any new medication, always check with your doctor first," says Dr. Attarian.

    Fixes: If your meds are causing sleep problems, "First, I’d suggest talking to your physician to see if your medication can be changed or the dose adjusted," says Dr. Attarian. "If that doesn’t work, you can go to a sleep clinic to discuss treatment options that may or may not include sleep aids. Taking a sleeping pill is not always the right thing right away especially if you are taking other medications to manage health conditions."
  • 4 A warm bath
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    Body temperature naturally begins to drop before bedtime, preparing us for sleep. Although a warm bath can relax and calm you, taking one too close to bedtime will not give your body enough of a chance to cool sufficiently to bring on slumber.

    Fixes: To reap the full benefits of your bath, the National Sleep Foundation recommends finishing up your soak at least an hour before climbing into bed. While you’re at it, keep your room cool. "We sleep better in cool rooms," says Patrick D. Lyden, M.D., chairman of the Department of Neurology at Cedars-Sinai Medical Center in Los Angeles, California.
  • 5 Choosing the wrong foods
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    If you like to snack before bed, watch what you eat. Loading up on foods that contain excessive salt or fat can stimulate brain waves, bringing on nightmares instead of sweet dreams, says the National Sleep Foundation. Choose foods that contain tryptophan (an amino acid linked to sleep quality), whole-grain carbs (which help boost serotonin production) and certain minerals (like calcium and magnesium, which can have a calming effect). Examples include half a banana and a handful of almonds, whole-grain crackers and peanut butter, a mug of warm milk, or half a turkey sandwich on whole-wheat bread.

    Fix: In general, stick to a routine of eating early in the evening and try to avoid sugar at night. "Late meals are more likely to make it harder to sleep; snacking in the middle of the night can worsen insomnia," says Andrew J. Westwood, M.D., a member of the American Academy of Neurology and American Academy of Sleep Medicine. Additionally, eating too much can make you feel physically uncomfortable when you lie down, and may cause heartburn, contributing to wakefulness.
  • 6 Clutter
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    The ideal bedroom should be simply furnished and decorated, so there’s not much to distract you from the primary reason you’re in there—to sleep. Excess clutter and mess can often cause anxiety, and remind you of all your unfinished business, making it harder to fall—and remain—asleep.
  • 7 Exercise
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    Sure, being physically active can make you tired, promote sleep, and improve the quality of your rest, but exercising vigorously too close to bedtime can rev you up instead. "Aerobic exercise can raise your core body temperature long after you’ve finished," says sleep specialist Rubin Naiman, Ph.D.

    Fixes: Dr. Naiman suggests completing exercise at least three hours prior to bedtime. However, gentle exercise like yoga, he says, can be helpful to promote relaxation and sleepiness.
  • 8 Stress
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    When you’re stressed, your body secretes cortisol, a hormone produced by the adrenal gland. This can disrupt the body’s natural rhythm, says Dr. Naiman. "Cortisol is naturally produced in the morning. It peaks at around 8am, when it can be helpful to naturally energize us,” he explains. "But at the wrong time—like nighttime—it can make us hyper-aroused and disrupt our sleep."

    Fixes: In addition to yoga for relaxation, a new study in adults over 55 finds that practicing a popular form of meditation known as mindfulness meditation can reap improvements in sleep quality, and reduce insomnia and fatigue. Mindfulness meditation can also help reduce stress, according to a 2009 Massachusetts General Hospital study. Visit to learn some basics.

    If meditation is not your thing, there’s always a good old-fashioned belly laugh; laughter actually induces physical changes in your body, says the Mayo Clinic. It cools your stress response and can increase positive thoughts, which, in turn, causes your body to release neuropeptides to help fight stress.
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