How Does Sleep Affect Your Brain?

Did you know that not getting enough sleep can harm the health of your brain? Sleep deprivation is associated with an increased risk of several chronic conditions including obesity, diabetes, high blood pressure, heart disease, and stroke.1 However, a sufficient amount of sleep is also key to optimizing several brain functions, including mood, memory, and decision-making. 

Sleep is critical to the health of the brain in several ways. In the short term, a poor night’s sleep can result in drowsiness, reduced alertness, and decreased concentration. When you are deprived of sleep over a long period of time, you are more likely to develop anxiety reactions or feel depressed. A long-term lack of sleep can also lead to mental risks such as paranoia, mania, hallucinations, and suicidal thoughts.  

Your brain is able to naturally remove toxins while you are asleep. Microglial cells, a type of nerve cell localized in the brain and spinal cord, help to remove beta-amyloid, a toxic protein that is commonly found in the brains of those who suffer from Alzheimer's disease. Astrocytes, which are star-shaped nerve cells of the central nervous systm, are also hard at work while you are asleep, repairing neural synapses. Both microglial cells and astrocytes can help with nerve tissue repair while you sleep, but if you are sleep-deprived, these cells may attack healthy brain tissues instead.2  

In addition, when you are sleep deprived, your brain processes its surroundings much more slowly. In one study, this slower response had a similar influence on the brain as drinking too much alcohol.3 Memory and decision-making can become impaired when the synapses in your brain fire more slowly. In fact, even a link between exhaustion and road traffic accidents has been shown – it is estimated that hundreds of deaths occur in the U.S. every year by drivers dozing off at the wheel.  

The CDC estimates that over one third of American adults do not get the recommended 7 to 9 hours of regular sleep each night.4 For better sleep, experts recommend removing electronic devices such as laptops, cell phones, and televisions from the bedroom or turning them off an hour or two before going to bed. The blue light emitted by the electronic screens of these devises can also alter your natural circadian rhythms and make it more difficult for you to doze off.

Sticking to a regular sleep routine – rising and going to bed at the same time each day, even on weekends – and making your bedroom as dark and quiet as possible can also have profound impacts on your quality and length of sleep. Though it may be tempting to stay up late to watch a movie, finish the next chapter of a great book, or have a late night out with friends, a better choice may be to stick to your regular sleep schedule and re-schedule the late-night activities to an earlier time. A renewed sense of healthy mood, memory, and brain health will be your great reward.  


  1. “Brain Basics: Understanding Sleep.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services,
  2. Bellesi, Michele, et al. “Sleep Loss Promotes Astrocytic Phagocytosis and Microglial Activation in Mouse Cerebral Cortex.” The Journal of Neuroscience : the Official Journal of the Society for Neuroscience, Society for Neuroscience, 24 May 2017,
  3. Nield, David. “Sleep Deprivation Has The Same Effect as Drinking Too Much, Says Study.” ScienceAlert, 
  4. “1 In 3 Adults Don't Get Enough Sleep.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 16 Feb. 2016,
  5. Harvard Health Publishing. “Blue Light Has a Dark Side.” Harvard Health,