This Is What Happens When You Don't Get Enough Sleep, According to the Experts

Close up of an unmade bed in the sunlight

Stacy Allen / Stocksy

We all know that sleep is vital to our overall wellness. But you maybe haven't taken the time to fully understand exactly why—or what—the ramifications of not sleeping well are. One poor night's sleep may not be a big deal, but if the trend continues, you might be surprised by how much negativity it can bring into your life. "Getting ample sleep is essential for maintaining physical and mental health," says neuropsychologist Sanam Hafeez, PsyD. "Chronic sleep deprivation can seriously affect your well-being."

We tapped Hafeez and clinical psychologist Shelby Harris, PsyD, to help us understand everything that happens when you don't get enough sleep. Read on to learn why those eight hours are so important.

Meet the Expert

  • Shelby Harris, PsyD, is a licensed clinical psychologist and the sleep health director of Sleepopolis.
  • Sanam Hafeez, PsyD, is a neuropsychologist and director of Comprehend the Mind.

What Happens When You Don't Get Enough Sleep?

Your Immune System Suffers

Your sleep directly translates to your wellness. "When we sleep, our immune system produces certain proteins and antibodies that we need to help fight off diseases or infections," says Harris. "If you are sleep deprived or not getting enough sleep, your immune system decreases the production of those disease-fighting cells. This can disrupt your immune system and increase your chances of getting sick." "It's important to prioritize sleep as part of your overall health and wellness routine to help keep your immune system functioning properly," adds Hafeez.

Your Risk of Disease Increases

Because your immune system gets weakened by too little sleep, it becomes harder to fight off disease. Hafeez tells us more about the proteins that Harris referenced, explaining that "as you sleep, the body produces cytokines, proteins that help fight off infections and inflammation. A lack of sleep may cause your body to produce fewer cytokines, weakening your immune system's ability to fight infection."

There's no shortage of illnesses that a lack of sleep can cause, either. "Sleep deprivation can lead to increased stress hormones such as cortisol, which can also negatively impact the immune system by putting you at higher risk for conditions such as diabetes, heart disease, and obesity," says Hafeez.

Your Mood Isn't As Easily Regulated

You've likely noticed that tired people are often unpleasant and in a bad mood. You can blame that (at least partially) on the sleep loss. "Poor sleep quality and/or quantity can also lead to difficulty regulating mood and emotion," explains Harris. "Depression, anxiety, and stress can increase if someone is routinely not getting enough sleep."

Hafeez notes that the increased anxiety and stress can potentially lead to problems at work or school. These mental health issues can worsen if you continue sleeping insufficiently.

Your Memory Can't Function Properly

If you've noticed that you don't remember the events that occurred around a time you weren't sleeping well, then you already understand how sleep affects memory. "While sleeping, the brain is consolidating our memories from the day and storing them in case we need to remember them in the future," Harris says. "A lack of sleep can significantly affect this process and make it more difficult for us to recall those memories."

"Lack of sleep can significantly impact memory, both in the short and long term," adds Hafeez. "It has been shown that sleep strengthens the neural connections that form memories. When you are sleep-deprived, those neurons become overworked and cannot function properly, affecting how you process and retain information."

It Becomes Harder to Learn New Things

Ever felt like your brain just couldn't cope with a new task or skill when you were sleep deprived? That's because for your brain to work properly, your body needs sufficient sleep. "Sleep deprivation can cause impaired attention, reduced consolidation leading to weaker memories, impaired recall of information and memories, memory distortion causing confusion and muddling, and difficulty retaining new information," says Hafeez.

Harris concurs: "Sleep deprivation also reduces cognitive function and processing which can affect our ability to recall and/or learn new information effectively," she says.

How Much Sleep Should You Be Getting?

"It is recommended that adults and young adults get anywhere between seven and nine hours of sleep a night" for adequate rest, says Hafeez, adding that "it's rare for a person to function properly on less than six hours of sleep per night, and those who claim that's all they need have more than likely begun to adapt to the effects of sleep deprivation.

That being said, she emphasizes that there isn't a perfect one-size-fits-all answer to this question. "The adequate hours of sleep a person needs can depend on various factors, especially age, sleep quality, and previous sleep deprivation," she notes.

The Final Takeaway

Not sleeping enough directly impacts both your physical and mental health, leading to problems such as increased risk for disease and difficulty making memories. If you've been having a challenging time getting enough shut-eye, gaining a better understanding of sleep hygiene—which is your daily practice regarding sleep—may help. If you haven't been sleeping well, don't despair; better nights are on the horizon.

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