Here’s What Happens When You Don’t Get Enough Sleep

Here’s What Happens When You Don’t Get Enough Sleep

Stress, weight gain and forgetfulness are just a few effects of losing sleep

Up to 70 million Americans are sleep-deprived. But those hours of lost sleep add up to a bigger health deficit than you may realize, says sleep medicine specialist Nancy Foldvary-Schaefer, DO, MS.

“Sleep is foundational to health and wellness,” Dr. Foldvary-Schaefer says. “We know that getting enough sleep and getting enough good sleep is necessary for cardiovascular health, metabolic health and even brain health.”

Exactly how is a lack of sleep harmful to your health? Let’s take a look at what happens to your body when you don’t get enough rest.

Why lack of sleep impacts your body

There are lots of reasons why you need sleep. It allows your body to:

Conserve and store energy.

Repair and recover from daily activity and injuries.

Rest, reorganize and re-catalog your brain.

“Sleep is an active process for every organ of the body, including the brain,” Dr. Foldvary-Schaefer says. “We need sleep so we can restore nutrients, clear toxic materials and recharge for the next day.”

Even missing as little as 1.5 hours can have an impact on how you feel, causing short-term problems like:

Lack of alertness.

Memory problems.

Moodiness and agitation.

An inability or unwillingness to participate in normal daily activities.

“During periods of sleeplessness, hidden health hazards accumulate that can’t be covered up with concealer or reversed with caffeine.” Dr. Foldvary-Schaefer notes. “Everything from your cardiovascular system to your immune system feels the impact.”

The health effects of sleep deprivation

Beyond feeling groggy feeling and sleeping past your alarm, sleep deprivation affects many parts of your body and brain.

So, what exactly happens when you don’t get enough ZZZs? Let’s take a look at the many possible effects of sleep deprivation.

Fatigue and a lack of energy

If your internal batteries feel depleted by the early afternoon, that’s a clear sign of lack of sleep — and no, a late-day cup of coffee won’t cure it.

“If you wake up in the morning and you aren’t refreshed, and you feel exhausted or are yawning excessively during the day, those are all signs of insufficient sleep or another sleep disorder,” Dr. Foldvary-Schaefer states.

Sleep deprivation causes fatigue, low energy and excessive sleepiness, which can affect your ability to do things you love and simply complete day-to-day tasks.

Poor balance and coordination

If you’re stumbling through the day with fewer than seven hours of sleep, you’re likely to start literally stumbling.

A 2021 study found that sleep deprivation had a significant negative effect on gait (the way you walk), while other studies have found that a lack of sleep can affect your sense of balance. Both can put you at risk for accidents, falls and injuries.

Mood changes and mental health issues

It’s no big revelation that a night of bad sleep can make you feel irritated, emotional and short-tempered the next day. And chronic sleeplessness can quickly morph into mental health concerns.

“Mood disorders like depression and anxiety are also connected with chronic insomnia and sleep deprivation,” Dr. Foldvary-Schaefer cautions.

For example, research shows that people with insomnia are twice as likely to experience depression. It also shows that about 80% of people with depression experience insomnia.

In other words, sleeplessness can be a symptom of mental health issues, but it can also be a contributor to them, which creates a frustrating chicken-and-the-egg cycle.

Forgetfulness and neurological concerns

Wait, where did I put my keys? A lack of sleep affects your ability to remember and react, which can cause your brain to go blank on the most routine of tasks.

Deep stages of sleep are responsible for learning and memory. These include rapid eye movement (REM) sleep and deep non-REM sleep (also known as Delta sleep or slow-wave sleep, or SWS).

“When sleep is interrupted or cut short by going to bed too late or not getting eight hours in bed at night, your brain isn’t able to properly catalog its memories,” Dr. Foldvary-Schaefer explains.

She points to studies that show that students who pull all-nighters don’t do any better on their tests the next day: “Even though they’ve put in more hours, they’ve deprived themselves of the sleep that was needed to really ingrain those memories into their brains,” she says.

Sleep deprivation can also cause neurological disturbances like:

Blurred vision.

Memory lapse.

Poor reaction time.

“Deep sleep allows our brains to clear the toxins that accumulate during our waking hours,” Dr. Foldvary-Schaefer explains, “so that we don’t develop neurodegenerative diseases like Alzheimer’s disease.”

Research shows that this process takes seven to eight hours (and sometimes more). In other words, if you’re losing sleep, so is your brain.