Why quality sleep matters

Most of us know it’s important to get enough quality sleep, but how many of us really understand what that means? Or why it’s so important?

A simple way to explain why quality sleep matters is: Sleep acts like a personal butler – managing our bodies, overseeing key functions and helping keep everything in order. Like a butler maintains a house inside and out, sleep helps keep your brain, heart and immune system in tip-top shape. It also helps recharge your energy, balance your emotions and behavior, solve problems, make decisions, store memories and much more.

The difference is: Butlers usually get paid in money, while sleep’s main currency is time – ideally about seven to nine hours a night for most adults. Children and adolescents typically need more on average. And toddlers and infants need even more.

What happens when you don’t get enough sleep

Even one night of bad sleep can leave you feeling groggy, down and cranky. It can make it harder to stay alert, think clearly and have enough energy to do your day-to-day activities.

When a poor night of sleep here and there turns into ongoing sleep deprivation, it can lead to a range of serious health concerns, including:

• Daytime sleepiness that leads to increased risk of injuries and accidents

• Disrupted memory, concentration and decision-making

• Increased risk of developing depression and anxiety

• Higher blood pressure and cholesterol, along with a greater risk of heart disease and stroke

• A slower metabolism (meaning, your body’s ability to burn calories and turn them into energy) and an increased chance of developing type 2 diabetes or obesity

• A weakened immune system, making it harder to fight off illness

• Heightened pain sensitivity, making pain feel more intense

What defines quality sleep

Quality sleep involves cycling through four distinct sleep stages repeatedly throughout the night. Each one serves a specific purpose.

Sleep stages

• Stage 1 is your lightest sleep. It begins just after you fall asleep and lasts only a few minutes. It’s your body’s initial wind-down – systems start to slow down, including your breathing and heartbeat.

• In Stage 2, you move into deeper sleep. Your body temperature drops, and your brain begins storing memories, including what you’ve learned during the day. This stage makes up about half of total sleep.

• Stage 3 is your deepest sleep, when your body goes into recovery and maintenance mode. Your blood pressure, heart rate and breathing reach their lowest levels. It’s difficult to wake someone up during this stage. If you are woken up, you probably feel confused and disoriented. This stage can tally up to about 25 percent of total sleep.

• Stage 4 is rapid eye movement (REM) sleep. This is when you dream the most. While more research is needed, scientists believe REM sleep helps us process emotions. This stage makes up to about 25 percent of total sleep.

A full sleep cycle – meaning, moving through all four stages – takes about 90 minutes to two hours. Completing these cycles four to six times per night is what defines a good night of quality sleep.

Because your body needs to go through multiple full cycles to get the restorative benefits, napping or trying to “catch up” on weekends doesn’t really work to fully restore your body and mind. You usually don’t reach the deeper stages during a nap, and if you try to cram sleep in on a day off, your body still misses the regular “housekeeping” it needs to support your health and well-being.

How your body knows when to sleep

Your circadian rhythm helps you stay on track to fall asleep and sleep long enough for the brain to complete its nightly housekeeping. It’s the internal clock that helps control your rest-wake cycle, based on the light of day, dark of night and other environmental cues. When night falls, it signals your brain to release the hormone melatonin, which makes you feel sleepy. It also helps cool your body temperature and slows your breathing and heart rate to help prepare you for sleep.

The clock keeps ticking all night. When daylight approaches or it’s your natural time to wake up, it signals your brain to start waking you up by warming your body and raising your breathing and heart rate.

Just like a regular clock, your internal clock can get off track, too. For example, traveling to a different time zone can disrupt it. So can having a sleep disorder that interferes with your sleep patterns and makes it hard to sleep soundly.

Signs you’re not getting enough quality sleep

While the effects of sleep deprivation can vary from person to person, common signs and symptoms include:

• Feeling tired during the day

• Falling asleep or napping during usual waking hours

• Trouble focusing, remembering things or staying alert

• Slowed thinking and delayed responses

• Irritability or mood swings

• Headaches

• Falling asleep briefly during the day (sometimes called “microsleeps”)

• Trouble speaking clearly

• Shaking hands

• Hallucinations

• Impulsive or reckless behavior

Sleep disorders

Two of the most common sleep disorders are insomnia and obstructive sleep apnea (OSA). Both can lead to sleep deprivation, especially if left untreated, and can put you at greater risk for developing serious health concerns, like those listed above. It’s important to seek diagnosis and treatment from a health care provider.

People who have insomnia have a lot of trouble falling asleep and staying asleep. They also tend to feel like they can’t turn their brain off or stop thinking. About 12 percent of people in the United States have insomnia.¹

Obstructive sleep apnea (OSA) is a serious condition that affects up to an estimated 30% of adults.^2,3 People who have this disorder stop breathing for short periods periodically through the night. That’s because when you have sleep apnea, your tongue relaxes back into your airway during sleep and blocks airflow, making it difficult to breathe regularly. Each time you stop breathing, your brain alerts you to wake up and take a breath. If this happens five or more times per hour, it prevents you from getting the deep, restorative sleep your body and mind need.

People who have sleep apnea may not remember waking up, but they may notice other signs and symptoms, like those listed above, as well as snoring loudly or waking up with a dry mouth or sore throat.

Other reasons someone may not get enough quality sleep include:

• Lifestyle factors, like working overnight or rotating shifts, drinking alcohol or caffeine or using screens (such as on a TV, phone or laptop) too close to bedtime.

• Short-term illnesses, like the common cold or flu.

• Mental health conditions, such as depression, anxiety or post-traumatic stress disorder (PTSD).

• Medical conditions, such as chronic pain or neurological conditions.
  

Talk to a health care provider

A wide range of treatments are available to manage sleep deprivation and sleep disorders – from adjusting behaviors and routines to over-the-counter dental appliances, prescription medical devices and medications.

If you’re struggling to consistently get enough quality sleep, talk to a healthcare provider or mental health professional. They can help assess the symptoms and offer a diagnosis and treatment plan tailored to your unique situation, medical history and lifestyle needs.

Tips for improving sleep

In the meantime, here are some tips for getting better sleep:

• Going to bed and waking up at the same time each day.

• Avoiding screens and bright lights before bed.

• Avoiding caffeine, nicotine, alcohol or sedatives.

• Getting exposure to morning sunlight.

• Staying active and exercising regularly.

• Creating a quiet, cool, dark and comfortable sleep environment.

• Maintaining a healthy weight.

Prioritizing quality sleep is one of the best things you can do for your long-term health – consider starting with a few small changes tonight.

Sources

1 American Academy of Sleep Medicine, 12% of Americans are diagnosed with chronic insomnia.

2 American Medical Association, What doctors wish patients knew about sleep apnea. April 1, 2022.

3 Cleveland Clinic, Sleep Apnea: What It Is, Causes, Symptoms & Treatment. January 15, 2025.

American Brain Foundation, Why Sleep Is Important for Brain Health. March 16, 2022.

Cleveland Clinic, Sleep Deprivation: What It Is, Symptoms, Treatment & Stages. August 11, 2022.

Loyola Medicine, The Silent Threat of Sleep Apnea: Why Ignoring Symptoms Can Be Dangerous. December 19, 2024.

Mayo Clinic, Insomnia - Symptoms and causes. January 16, 2024.

National Institute of Neurological Disorders and Stroke, Brain Basics: Understanding Sleep. Accessed June 21, 2025.

Obesity Medicine Association, Obesity and Sleep Apnea: Understanding the Connection. November 18, 2024.

SleepApnea.org, How Weight Affects Sleep Apnea. May 11, 2023.

Sleep Foundation, Mental Health and Sleep. March 26, 2024.

Sleep Foundation, Why Do We Need Sleep? April 5, 2024.