What Are The Consequences Of Poor Sleep?

Last updated: March 14, 2019

In today’s society, people are so busy that they usually cut back on sleep for their studies or work. Staying up all night to meet a deadline has almost become a norm. A norm with a cost.

Sleep loss isn’t the only thing that causes various consequences, but also poor or inadequate sleep. Some problems we may encounter after a sleepless night are poor attention, bad mood and the like. However, not many people are aware of or care about the long-term consequences of inappropriate sleep.

These include a high risk of heart diseases, chronic health problems, sleep disorders, depression or Alzheimer’s disease. Here we talk about the poor and insufficient sleep, their consequences, and how to prevent them.

Poor and insufficient sleep

When we talk about poor sleep, we may think about the sleep of low quality, such as non-restorative sleep. This is when a person doesn’t reach the deep sleep (which is responsible for the feeling of freshness and high energy) and/or REM sleep (whose lack will leave us cranky). This can be caused by alcohol, extreme stress, sleep disorders, or illnesses. The result of such sleep is strong sleep inertia followed by excessive daytime sleepiness.

A person may not sleep well if the external factors are bad, too. High room temperature, the presence of light and sounds can impair sleep quality and cause either frequent wakings or non-refreshing sleep.

Some people might not be having enough sleep even though they think they do. This primarily refers to short sleepers – not the tiny percentage of people who are totally fine on 6 hours of sleep, but those who genetically and biologically need more sleep, but just not get it. They believe they are getting sufficient good night’s sleep, but are highly likely to develop health, mood, and immune system problems as a result of long-term sleep loss.

One of the big problems our society faces is sleep deprivation. Whether it is due to studying, working in shifts, or behavior like all-night partying, drinking, or even gaming, a substantial percentage of adults are sleep deprived. According to the Centers for Disease Control and Prevention (CDC), about 35% of adults in the US are not getting enough sleep.

‘Enough sleep’ here means the recommended 7 hours, but we shouldn’t forget that even seven is too little for some people. This brings up a scary question – does this mean that every third American behind the wheel is sleep-deprived?

What are the consequences of short-term and long-term sleep deprivation of poor or insufficient sleep?

Not sleeping enough causes a variety of imbalances in the body – whether they are chemical (hormones and neurotransmitters), mental, or physical. Even only one night of poor sleep has its consequences. During good, restorative sleep, harmful substances from our brains are ‘washed away’ from the system.

‘Instant’ consequences

When we don’t get the proper nightly ‘maintenance’, we wake up to overworked brain cells which are not ready for new challenges and stimuli. Here are the instant consequences and changes after a short time of sleep loss:

  • Excessive daytime sleepiness and sleep inertia. Poor or too short sleep usually end in an inability to easily get out of bed, dragging the sleepiness with us. This grogginess is known as sleep inertia and is one of the biggest causes of morning traffic accidents.  Fatigue, weakness, and the need for napping frequently follow a sleepless night.
  • Poor attention, bad decision making and slow reaction time. This can be dangerous, especially if a tired person is on a highly responsible position that involves physical work with heavy machinery, or making important decisions that make an impact on their business or other people’s lives.
  • Mood changes. When amygdala, the fear and emotion center is overworked, we tend to be moody and have inappropriate reactions in social situations. Our stress rises and we are under constant pressure. Good sleep gives us good feelings, replenishing serotonin, the happy neurotransmitter.
  • Difficulty learning. A tired brain can’t take new information well, has difficulty setting priorities and recalling. Students should pay attention to getting proper sleep.
  • Blood pressure increases. Blood pressure quickly changes due to insufficient sleep and increased stress.
  • Hormonal imbalances. In healthy young men, testosterone levels drop significantly after sleep deprivation. Hormones controlling our appetite fail to inform us we’ve had enough food, causing unintentional overeating. Moreover, insulin resistance significantly increases, bringing an otherwise healthy person to a state which is biochemically similar to that of a prediabetic person. Stress hormones are on a high level.

Long-term consequences

A prolonged period of many months or years of insufficient sleep increases the risks of a plethora of diseases and health problems.

  • Obesity and diabetes. With the body unable to process food well and increased cravings, many people who have sleep problems also have weight problems. The constant, chronic insulin resistance caused by poor sleep is believed to lead to diabetes.
  • Cardiovascular diseases and hypertension. Studies have shown that people who sleep both less and more than they actually need are at high risk of developing cardiovascular diseases. As the blood pressure was frequently increased, chronic sleep deprivation is likely to cause chronic hypertension.
  • Anxiety, depression, emotional instability. If the brain is constantly overworked and ‘jammed’ with information which keeps arriving but has no chance to properly take a break, some mental problems may develop. They can get more severe with longer sleep deprivation. Proper sleep should reverse mood for the better, at least to some extent.
  • Poor memory and an increased risk of neurodegenerative diseases. Alzheimer’s disease is one of the most famous examples of a neurodegenerative disease. It is associated with adenosine plaque buildup. Adenosine is found in every human because it is a substance produced from brain cell activity – it also makes us feel tired. When we sleep, it is cleared out. When we don’t, it’s not, remaining in the space between cells. If the brain is not given the chance to clean from adenosine for a prolonged period of time, it may build up, becoming a neurotoxin (meaning that it harms and kills brain cells).
  • The immune system suffers from inadequate sleep, leaving a person prone to getting sick, from the common cold to more serious illnesses.

What sleep disorders might occur as a consequence of poor and insufficient sleep?

So far, we’ve talked about health problems that arise from insufficient sleep. However, there are many consequences related to future sleep quality. This means that bad sleep habits after some time can result in sleep disorders. It could take a lot of make-up sleep days or weeks before symptoms retreat. Note that most of these disorders occur in exhausted, sleep deprived individuals who also indulged in unhealthy behaviors, like consuming drugs and alcohol which ‘broke’ the brain’s sleep-wake flip-flop switch.

  • Sleep paralysis. It is normal for the body to be paralyzed during REM sleep – this is how we are unable to act out our vivid dreams (and possibly hurt ourselves or others). However, in sleep paralysis, a person first ‘wakes up’ – becomes partially conscious, while the body is still paralyzed. This inability to move frequently causes fear and strong discomfort, especially as the person might feel an inability to breathe properly.
  • Hypnagogic hallucinations. These are hallucinations which occur seconds before sleep, while the person is still awake. Sometimes a person may have hallucinations about sounds or someone’s presence.
  • Narcolepsy. This is a disorder in which a person is extremely tired, falling asleep easily, even involuntarily. One of the characteristics of narcolepsy is that the person might fall directly into REM sleep, or even begin dreaming before sleep onset.
  • Cataplexy is an involuntary body paralysis which after strong happy emotions (like laughter). Although it happens in wakefulness, cataplexy is characterized by REM sleep atonia (paralysis).
  • Sleepwalking in adults is sometimes a sign of sleep deprivation. It can occur due to genetics, especially in children. However, adults usually stop sleepwalking after some time of good night’s rest.

Why do I feel happy after pulling an all-nighter?

Some people feel euphoria after a single night of staying awake because of the dopamine surge. Dopamine is known to make us feel happy, but it also blocks ‘sleepy’ hormone melatonin. So, when we make an effort to remain awake against all odds, our body might boost dopamine in order to keep us awake.

However, this is only a one-time thing and it doesn’t happen to everyone – depressed people seem to have a higher dopamine surge, which is why one-night sleep deprivation is sometimes used to treat depression.

However, soon all the symptoms of sleep deprivation will become visible. Some authors warn about this phenomenon because they have found that sleep deprivation makes people optimistic, but very poor decision makers. Therefore, be careful when it comes to the all-nighter euphoria.

How to avoid sleep deprivation consequences?

First, if you are sleep deprived, make yourself some good sleep time within a certain schedule. Routine seems to be one of the best friends of restorative sleep.

  • Your sleep-wake cycle should have approximately the same pattern every day.
  • Avoid the nightcap. Alcohol doesn’t allow you to reach deep sleep, which is extremely important for restoration and refreshment of the body and the brain.
  • Have exercises and plenty of sunlight during the day.
  • Avoid technology use, big meals, and caffeine before bed.
  • Sleep in a dark (if possible, pitch-black) and cool room for the best rest.
  • Take short naps during the day – it is a better solution than coffee.


There are many more rules to follow if you want to have healthy sleep and relieve some of the consequences of long-term exhaustion.

Additional resources

  1. 1 in 3 adults don’t get enough sleep. Centers for Disease Control and Prevention. https://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html Accessed March 13, 2019.
  2. Donga E, van Dijk M, et al. Single Night of Partial Sleep Deprivation Induces Insulin Resistance in Multiple Metabolic Pathways in Healthy Subjects. The Journal of Clinical Endocrinology & Metabolism. Volume 95, Issue 6, 1 June 2010. https://academic.oup.com/jcem/article/95/6/2963/2598810#52732609 Accessed March 13, 2019.
  3. Grandner M. A, Patel N. P, et al. Problems Associated with Short Sleep: Bridging the Gap between Laboratory and Epidemiological Studies. Sleep medicine reviews. November 6, 2009. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2888649/ Accessed March 13, 2019.
  4. Gujar N, Yoo S. S, et al. Sleep Deprivation Amplifies Reactivity of Brain Reward Networks, Biasing the Appraisal of Positive Emotional Experiences. Journal of Neuroscience. March 23, 2011. http://www.jneurosci.org/content/31/12/4466Accessed Accessed March 13, 2019.

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