How Many Hours of Sleep Do You Really Need?

Medically Reviewed on 8/16/2022
How Many Hours of Sleep Do You Really Need?
Your sleep quality strongly influences how you feel during the day, as well as your physical and mental health.

Sleep is essential for the proper functioning of practically every organ system in the body. However, various factors may influence your hours of sleep including:

  • Medical issues
  • Hectic schedule
  • The natural act of aging
  • Genetic predisposition

Your age is the most important factor that decides how much sleep you require, and the National Sleep Foundation accordingly recommends sleep hours per age group.

There is no single number that suits everyone because everyone is different. The only way to determine how much sleep you require is by paying attention to your body’s needs. If you wake up feeling lethargic, you may need to adjust the number of hours you sleep each night.

Still, adopting the suggested hours as a starting point is a solid first step.

Recommended hours of sleep chart

Table 1. Sleep hours per age group according to the National Sleep Foundation.
Age group Age Recommended hours of sleep
Newborn 0 to 3 months 14 to 17
Infant 4 to 11 months 12 to 15
Toddler 1 to 2 years 11 to 14
Preschool 3 to 5 years 10 to 13
School-age 6 to 13 years 9 to 11
Teen 14 to 17 years 8 to 10
Young adult 18 to 25 years 7 to 9
Adult 26 to 64 years 7 to 9
Older adult 65 years or older 7 to 8

What is the effect of sleep on your health?

Sleeping may appear to be an opportunity to relax, rest, and dream; however, it has a greater influence on your health and lifestyle than you may realize. Your sleep quality is strongly related to and influences how you feel during the day, as well as your physical and mental health

Here are some of the reasons why a good night's sleep is essential: 

  • Influences your hormones that are responsible for hunger, metabolism, growth, and healing (children and young adults produce growth hormones during deep sleep, which helps with their growth spurt)
  • Improves productivity, attention, focus, and creativity
  • Improves athletic performance, response time, and mobility
  • Controls and assists in weight management
  • Reduces the risk of heart disease and stroke while promoting heart health
  • Strengthens the immune system and aids in the healing of illnesses
  • Reduces the risk of chronic health issues such as obesity and diabetes
  • Aids in the treatment of mental health conditions such as depression and anxiety

Not the hours of sleep but how deep the sleep plays a major role in providing you with the best results.

What is deep sleep and its importance?

When you sleep, your brain goes through normal activity cycles.

There are four stages of sleep in all, separated into two phases:

  1. Nonrapid eye movement (REM):
    • Non-REM sleep occurs initially and is divided into three phases. 
    • The third stage of non-REM is known as deep sleep. 
    • Your body relaxes during the third stage of non-REM and results in a decrease in breathing, pulse, and muscle tone.
    • Deep sleep is responsible for all major changes and improvements in your body such as:
      • Boosts immunity
      • Improves memory
      • Regulates hormones
    • It is difficult to awaken from this stage of sleep.
    • Deep sleep usually lasts for 20 to 40 minutes during the whole sleep cycle. You will have good health benefits if you have a more deep sleep.
  2. REM:
    • REM sleep occurs between an hour and an hour and a half after falling asleep. 
    • REM sleep is characterized by vivid dreams.
    • When you sleep, your body cycles between non-REM and REM sleep. 
    • Non-REM sleep is the most common stage of the sleep cycle. 
    • You go through non-REM sleep stages before entering a brief period of REM sleep. 
    • The cycle is then reset to the stage.

A whole sleep cycle lasts 90 to 110 minutes. Your initial REM cycle is brief. You will experience more REM sleep and less deep sleep as the night progresses.

SLIDESHOW

Sleep Disorders: Foods That Help Sleep or Keep You Awake See Slideshow

What are the 5 negative effects caused by poor sleep?

Studies have suggested that chronic sleep disorders have been linked to an increased risk of significant health diseases, such as:

  1. Heart diseases: 
  2. Immune function: 
    • The immune system works properly by releasing chemicals that fight diseases and heal the body.
    • Due to improper sleep, the immune system dysfunctions, and thus, you feel fatigued. 
  3. Obesity: 
    • People who sleep fewer than six hours every night are more prone to obesity. 
    • Research has suggested that inadequate sleep disrupts the hormonal balance that regulates food and metabolism.
  4. Diabetes
    • Type II diabetes is commonly seen in people who do not get enough sleep. 
    • It may be due to the slower digestion of glucose.
  5. Depression:

Studies have suggested that people who received seven and eight hours of sleep per night had lower mortality rates than those who had significantly less or significantly more hours of sleep per night.

Medical experts are still attempting to figure out how this all works, but it is well established that sleep disturbances pose a significant health risk.

What are the 6 factors that influence sleep quality?

Six factors that affect your sleeping hours and quality of sleep include:

  1. Genetic mutations:
    • A genetic mutation may be the reason you tend to sleep late. 
    • CRY1 gene influences your circadian cycles and how exhausted you feel. 
    • If you are prone to CRY1 alterations, you have a longer circadian cycle than others, which keeps you active and away from sleep for extended periods.
  2. Gender:
    • Studies have suggested that women require deeper and longer sleep than men because women have more complicated processes occurring in their brains during sleep. 
    • On average, women sleep 15 to 20 minutes longer than men, especially women younger than 45 years.
  3. Emotions such as anger or anxiety:
    • Anxieties, disputes, or relationship disturbances in the night not only prohibit you from falling asleep but also have a bad effect on your body.
    • Wandering thoughts, heated emotions, and anger will keep you awake.
    • You need sleep, but to sleep properly and wake up feeling great, it is crucial to keep yourself away from unnecessary conflicts.
  4. Screen time before bed:
    • You should not use any electronic devices before going to bed. Watching TV can have a bad effect on your body and deprive you of quality sleep. 
    • It is scientifically proven that the usage of such devices interferes with the generation of the hormone responsible for sleep.
    • Therefore, if you want to fall asleep fast, avoid the use of all electronic devices at least one hour before bedtime.
  5. Alcohol consumption:
    • Many people believe that alcoholic beverages put you to sleep. However, hangovers and feeling ill are nearly always a part of this process.
    • Furthermore, the body gradually adapts to alcohol, eventually leading to less sleep.
    • Excessive alcohol drinking may rapidly lead to various health problems, including sleep disturbances. 
  6. Room temperature:
    • If your core body temperature is higher or your surrounding room temperature is on a higher side, it suffocates you and prevents you from sleeping.
    • Experts believe that the best sleep is obtained when the room temperature is somewhat chilly, that is about 16°. 
    • Thus, it is important to keep your room well ventilated before going to bed.
Medically Reviewed on 8/16/2022
References
Image Source: iStock image

How Much Sleep Do We Really Need? https://www.sleepfoundation.org/how-sleep-works/how-much-sleep-do-we-really-need

How Much Sleep Do You Need? https://www.helpguide.org/articles/sleep/sleep-needs-get-the-sleep-you-need.htm

How many hours of sleep are enough for good health? https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/how-many-hours-of-sleep-are-enough/faq-20057898