A Harvard doctor reveals how many hours you should sleep based on your age.

Eight hours of sleep. That's the number often mentioned when talking about the amount of time needed to get adequate rest. However, not all experts agree.

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The first thing you need to know is that getting a full night's sleep isn't just about rest; it 's also essential for physical, mental, and emotional health. This is supported by the fact that sleep acts as a restorative and regulatory process that influences almost every system in the body.

Now, regarding that mythical number, Dr. William Andrew Kormos of Harvard Medical School explained to National Geographic that while eight hours of sleep is often described as the ideal amount, it actually depends on the individual.

Optimal sleep hygiene typically ranges between seven and nine hours for adults, while eight hours is usually sufficient for older people. However, the expert emphasized that this flexibility in sleep schedules doesn't mean that reducing sleep doesn't have consequences.

Regularly getting too little sleep decreases concentration, attention, and memory. It also increases irritability, stress, and impulsiveness, in addition to increasing the risk of cardiovascular disease.

The balance point? Getting at least seven hours of rest, with the quality of sleep important for the body to assimilate.

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Recommended hours of sleep

- Preschoolers (3-5 years): 10 a.m. to 1 p.m.

- Schoolchildren (6-13 years): 9 to 11 hours.

- Teenagers (14-17 years): 8 to 10 hours.

- Young adults (18-25 years): 7 to 9 hours.

- Adults (26-64 years): 7 to 9 hours.

- Seniors (65+ years): 7 to 8 hours.

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