The Benefits of Sleep:
Why Is Sleep Important?
And Why We Need It?

Sleep is one thing most of us take for granted. After all, it’s something that just happens automatically every day of our lives, a natural function that, for the most part, we don’t have too much control over.

Given how essential sleep is for good overall health and wellbeing, it’s not something that should be taken for granted.

At OptimumSleep, it’s part of our mission to educate people about the benefits of sleep — and both physical and mental health are a big part of that.

This is why we’ve produced this guide that outlines exactly why sleep is so essential and the benefits you can expect to see when you consistently get the recommended amount of sleep each night.

Why Do We Need Sleep?

illustration representing sleep time Quite simply, we sleep because it is an essential function that our body requires.

You only need to miss out on one night of adequate sleep to realize how important it is for our everyday functioning.

If you’ve ever gone to work or school after an inadequate sleep or had a sub-par performance in sport or at the gym due to an insufficient sleep the night before, you’ll know this to be the case.

This is because sleep is when our body undergoes recovery and rejuvenation, both physically and mentally.

But sleep does more than just make you feel refreshed, more alert, and in a better mood. The overall health effects in both the short and long term run deeper than just a feeling of general wellbeing.

Good sleep makes your body more resilient to sickness and disease, both physical and mental, and can even result in a longer life expectancy. Let’s now look at some of the specific ways that sleep is vital for our overall health and well-being.

illustration of a bed

Why Is Sleep Important?

1. It’s Beneficial For Your Physical Health:

Getting adequate sleep is an integral part of physical health, from making our bodies more resistant to sickness to keeping our weight in check and allowing us to perform at our peak.

This guide will look mainly at the positive effects of sleep. To read about the potential adverse effects of too little sleep, see our guide on sleep deprivation and its impacts here.

1Immune System

Sleep is vitally important for your body’s ability to fight off disease and infection. You are less likely to get sick and more likely to recover from sickness faster if you are getting enough good quality sleep.

Here’s how sleep helps your immune system:

  • While you are asleep, your immune system produces proteins called cytokines, some of which promote sleep and which have a role in regulating immune system responses.
  • Your body requires levels of specific cytokines to increase when you are fighting infection or under stress.
  • Getting good enough good quality sleep helps promote the production of these cytokines and other antibodies and cells that fight infections.
  • Endocrine system activity during sleep promotes immune response and the formation of immunological memory, which allows your immune system to recognize previously encountered antigens and respond accordingly.
illustration representing immune system

2Heart Health

  • High blood pressure is one of the leading causes of heart disease and stroke. When we sleep, our blood pressure drops.
  • When we are sleep deprived, our blood pressure is at raised levels for longer, our blood vessels and cells don’t get a chance to heal and rejuvenate, and raised levels of inflammation-causing proteins may also cause extra strain on the heart.
  • Consistently getting a good night’s sleep can lower the risk of heart attack and stroke and keep your blood pressure at healthy levels long-term.
illustration representing a heartbeat


  • Some cytokines produced by the immune system are pro-inflammatory, making disease worse, while others are anti-inflammatory and promote healing.
  • Getting enough good quality sleep can help to reduce or eliminate chronic low-grade inflammation within the body by lowering the persistent production and release of pro-inflammatory cytokines.
illustration representing inflammation

4Athletic Performance

Proper sleep has been shown to enhance athletic performance.

Not only does getting the required amount of sleep put you in a more positive headspace that means you’re likely to be more motivated to undertake physical activity, but it can also boost your performance in the following ways:

  • It lowers levels of the stress hormone cortisol, which can cause fatigue and harm athletic performance.
  • Your body is able to better maintain glycogen and carbohydrate stores for energy; sleep deprivation can deplete them.
  • Improved attention, focus, reflexes, accuracy, and reaction time.
  • Improved physical performance in terms of speed, strength, and power.
  • Faster recovery.
  • Lower chance of injury.
illustration of a athelete

If you’re an athlete or someone with a physically demanding job or lifestyle, then you know the importance of good sleep and what a difference sleeping in the right bed can make.

Did you know one of our top-rated mattresses is designed with athletes in mind?

Read our reviews of the Bear mattress range, and learn about the unique FDA-approved technology these mattresses utilize that aids recovery and restful sleep for active people.

5Calorie and Weight Regulation

Sleep actually may help keep you looking lean and mean — not on its own, obviously. But if you maintain healthy sleep habits, you’re giving yourself an increased chance of successfully maintaining a healthy weight.

Studies have shown that there are fewer instances of obesity among people who get enough sleep.

Here’s why:

  • People who get enough sleep have lower levels of appetite and calorie consumption.
  • Getting the right amount of sleep keeps the production of the energy regulating hormone leptin at a healthy level.
    • Leptin inhibits hunger, resulting in lower food (and therefore, calorie) intake.
    • Lack of sleep results in lowered levels of leptin.
  • Shortened sleep can result in raised levels of ghrelin, the appetite-stimulating hormone.
    • Increased BMI is associated with raised levels of ghrelin and reduced levels of leptin due to sleep loss.
  • Lack of sleep can contribute to weight gain in other ways, such as decreasing motivation to exercise.
illustration representing calories

6Type 2 Diabetes

There appears to be a strong link between shortened sleep and developing type-2 diabetes.

  • Getting enough good quality sleep means your body has better insulin sensitivity and less insulin resistance.
  • With proper sleep, the body’s hormones are better regulated. This includes insulin (the hormone that regulates blood sugar), which is released when you eat.
  • Raised cortisol (which happens as a result of sleep deprivation) can prevent insulin from doing its job correctly, resulting in too much glucose in the blood, which increases the risk of developing type 2 diabetes.
illustration representing diabetes

7Life Expectancy

There are many benefits from healthy sleep that means those who regularly get the right amount of quality sleep and maintain a healthy sleep schedule generally have a better life expectancy than those who don’t.

Among the many reasons that can contribute to a healthier, longer life are:

  • Generally better mood; less depression, anxiety, etc.
  • Lower levels of stress hormones like cortisol.
  • It prevents chronic inflammation and lowers inflammation levels generally.
  • Lower risk of many potentially life-shortening diseases and health conditions.
  • Better cognitive function and performance.
  • Healthy sleepers are more likely to engage in beneficial physical activity.
  • Lowered risk of accidents.
illustration of an old man

2. It Encourages Healthy Brain Function and Emotional Wellbeing:

Sleep plays a significant role in our mental health, cognition, and emotional state as well.


  • REM sleep, in particular, is essential for memory, as this is the sleep stage where experiences are processed and consolidated into memories for recall later.
  • Getting enough good sleep allows for the uninterrupted creation of new connections in the brain.
illustration representing good memory


  • With good sleep comes a level of general alertness that means your ability to focus and concentrate is greatly elevated.
  • Concentration can affect memory, too, as the inability to concentrate on what’s at hand can mean it does not make it into your short-term and, eventually, long-term memory.
illustration representing concentration

3Emotions and Depression

Both your general mood and your risk of depression are linked to sleep.

  • A lack of sleep can significantly raise your risk of depression and suicide. People who experience depression are highly likely to experience insomnia and disturbed sleep, further exacerbating the problem.
  • Getting good sleep regularly lowers the risk of depression and can help raise your general mood, which also has its own health benefits.
illustration representing depression

4Social Interactions

Not only does suffering the effects of poor sleep bring our mood down, but it can also make us avoid interacting socially.

  • A positive mood makes us more likely to enjoy the company of others, while if we are depressed, we tend to isolate ourselves socially.
  • Not only do we tend to avoid socializing if depressed or down in the dumps, but social interactions can be made harder by sleep deprivation — it’s harder to read facial expressions, pick up social cues, and interpret the emotions of others.
illustration representing social interactions

3. It Allows for Optimal Daytime Functioning:


The combination of physical and mental/cognitive benefits that come from getting great sleep generally means that performance skyrockets — meaning better productivity at work.

  • Concentration
  • Problem-solving skills
  • Memory
  • Reaction time
  • Physical performance

All improve with sleep. So, if you’re looking for a raise at work, perhaps go to bed an hour or two earlier each night.

illustration representing productivity


It should not come as any surprise given the effects of good quality sleep on especially our brain that the risk of accidents, injury, even death can rise significantly in dangerous situations through a lack of sleep.

  • Drowsiness
  • Lack of concentration
  • Increased reaction time

These factors can lead to a higher chance of accidents, especially in dangerous workplaces, when driving, and in any situation where paying attention, recognizing danger, and reacting is required.

illustration representing safety

Are You Getting the Recommended Amount of Sleep?

The amount of sleep you need to be functioning at your best and avoid the raft of not-so-nice effects of sleep deprivation depends a lot on your age.

The average adult should be getting between seven and nine hours of good quality sleep each night.

Here’s what the recommended sleep breakdown looks like for all age groups:

Age RangeRecommended Sleep Duration
Newborn (0-3 months)14-17 hours
Infants (4-12 months)12-16 hours
Toddlers (1-2 years)11-14 hours
Preschoolers (3-5 years)10-13 hours
School Age (6-12 years)9-12 hours
Teenagers (13-18 years)8-10 hours
Adults (18-65 years)7-9 hours
Adults (65+)7-8 hours

For further reading on getting the optimal amount of sleep for your age, you can read our guide on how much sleep you need for your age here.

illustration representing advice

Tips & Good Habits to Ensure You’re Getting the Benefits of Enough Good Quality Sleep

  1. Practice good sleep hygiene. This doesn’t mean having a bath or shower before bed — in this context, “hygiene” refers to behaviors and practices rather than cleanliness. Sleep hygiene refers to practices like:
    • Sticking to a sleep schedule.
    • Following a pre-sleep routine that prepares you for sleep.
    • Creating a comfortable, distraction-free sleeping environment.
  2. Try to avoid electronic devices with screens before bed, especially if they emit blue light.
  3. Avoid alcohol and stimulants like caffeine several hours before bed.
  4. Exercise daily. Our bodies are designed for physical exertion. Getting plenty of exercise during the day can help to promote sleep at night.
  5. Eat a healthy diet. Maintaining an adequate level of general health is one of the best things you can do to encourage sound sleep.
One Last Suggestion

One last suggestion — ensure your bed is right for you. If your current mattress is old, worn out, not as comfortable as it used to be, or if you just don’t seem to be able to sleep well on it anymore, it may be time to consider replacing it.

To make sure you choose one that’s perfectly suited to you and your preferences; body size, sleeping position, and a range of other factors, check out our ultimate guide to choosing a new mattress here.