How many hours of sleep?

Since we were born — probably the last time we actually slept well — we are constantly told that 8 hours of sleep are necessary to function properly and stay healthy.

But between work, family, responsibilities, and the stresses of daily life , reaching this quota is often a challenge. In reality, many adults sleep an average of 6 hours a night .
So, is that enough?

According to experts, sleeping only 6 hours occasionally won't pose a major problem. However, chronic sleep deprivation can harm your health, concentration, and mood.
Here's what sleep science says — and how you can finally achieve those famous 8 restorative hours .

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🌙 Why is sleep so important?

In summary: poor sleep = poor health .
Of course, it's not quite that simple, but sleep is an essential biological function that allows the body and mind to regenerate.

Getting enough sleep supports:

• cardiac function ,

• brain development ,

• metabolism ,

• and the immune system .

Sleep also improves:

• memory ,

• learning ,

• mood ,

• and weight regulation ( source) ).

In other words, sleeping well is an investment in your physical and mental health .
👉 To learn more, check out the complete Good Sleep, Good Health guide .

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⏰ How many hours of sleep does our body really need?

The question has been debated for a long time. While the 8-hour rule is often mentioned, the ideal duration varies according to age and lifestyle.
Experts agree, however, on an average of 7 to 9 hours for a healthy adult ( source: CDC). ).

But then, is 6 hours of sleep really insufficient?

The short answer: yes .
Research shows that an adult sleeping less than 7 hours a night risks disrupting their sleep cycle and circadian rhythm ( learn more about the circadian rhythm) . ).
And this can prevent reaching the most valuable sleep phase: REM sleep .

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😴 The crucial role of REM sleep

REM sleep represents approximately 20 to 25% of the total sleep cycle in adults. To fully access it, one must sleep at least 7 to 8 hours .

It is during this phase that:

• The muscles regenerate .

• the cells repair themselves ,

• and the memories become more firmly established .

A lack of sleep, especially during this deep sleep phase, can impair memory , slow recovery and weaken overall health .
👉 To understand the mechanisms of sleep, read Sleep Basics – Cleveland Clinic .

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🧠 Sleep requirements chart according to age

Each age group has different needs. Here is a clear summary:

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🕕 And if 6 hours seems sufficient to you?

Some people claim to feel good with only 6 hours of sleep, but this is often just an illusion .
The body can get used to deprivation , but that does not mean it is functioning properly .
The cumulative effects of sleep deprivation are well documented ( see here). ).

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⚠️ Signs you're not getting enough sleep

Your body often sends clear signals:

• Persistent fatigue

• Difficulty concentrating

• Unstable mood

• Dull skin , weight gain , or frequent urges to nap

👉 If you have several of these symptoms, your sleep is probably not restorative .

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🌙 Quality sleep or quantity: which should be prioritized?

Quality sleep without sufficient duration remains incomplete.
In short, 7 continuous hours are better than 10 fragmented hours .
The two go hand in hand for truly restorative rest .

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🧩 The consequences of a lack of sleep

A chronic lack of sleep can cause:

• Cognitive and memory disorders

• Slow reaction and decreased alertness

• Increased cardiovascular risk

• Decreased immunity and hormonal imbalance

💡 These effects are detailed in studies by the National Institutes of Health (NIH) .

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🌿 Tips to improve your sleep quality

Good news: a few simple changes can improve your nights.

🕯️ 1. Create a relaxing ritual

• Avoid screens before bedtime

• Opt for reading , meditation , or a hot bath.

• Use a comfortable sleep mask to promote total darkness and relax your eyes

🛏️ 2. Take care of your environment

• Cool and quiet room (18–20 °C)

• Complete darkness

• Reserve the room for sleep and relaxation

📅 3. Maintain a regular routine

Your circadian rhythm thrives on consistency.
Try to go to bed and wake up at the same time every day .

☕ 4. Reduce caffeine and alcohol

Caffeine remains active for several hours — avoid it after 2 p.m.
As for alcohol , it disrupts the REM phase and reduces sleep quality .

🧘 5. Move regularly

Physical activity improves natural sleep ( source: Johns Hopkins) ).

📵 6. Avoid stimulation before bedtime

Blue light delays the production of melatonin.
Replace screens with a quiet moment.

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🌞 Natural and clinical solutions

Despite all your efforts, you may still suffer from unstable sleep .
Personalized approaches and clinically proven treatments can help you get back to deep sleep ( see CDC resources on sleep) . ).

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🧾 Conclusion: 6 hours is not enough!

Although 6 hours of sleep may sometimes seem sufficient, this is not the case for the majority of adults.
To preserve your mental, physical, and emotional health , aim for 7 to 9 hours of quality sleep — ideally in complete darkness with a good Horbu sleep mask 🌙

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🔍 To learn more:

• Sleep Foundation – How Much Sleep Do We Really Need?

• HelpGuide – Sleep Deprivation

• CDC – About Sleep

• Johns Hopkins – Exercise for Better Sleep