Find out - Why do we sleep, how much do we need of it!

Zee Media Bureau

New Delhi: Sleep is a naturally recurring state of restfulness for the body, and is one of our most basic human needs. In other words, sleep is an active period in which a lot of important processing, restoration, and strengthening occurs, and hence it is as necessary as food and water.

Although scientists simply don't know for sure why do we need to sleep, they believe it is to enable our bodies and especially our brains to recover.

Sleep consists of two basic states/stages - rapid eye movement (REM) sleep (also known as active sleep or paradoxical sleep) and non-rapid eye movement (NREM) sleep (also known as quiet sleep), which consists of four stages.

Studies have also shown that people tend to retain information and perform better on memory tasks after they sleep. Lack of sleep can adversely affect our overall health, making us prone to serious medical conditions, such as obesity, heart disease, high blood pressure and diabetes. Sleep deprivation may also lead to long-term mood disorders like depression and anxiety. Therefore everybody needs to have an adequate sleep for optimal health and wellbeing.

Scientists have also discovered that sleeping too little or too much is bad for the heart- less than 4 hours and more than 8 raises the risk of early death from heart disease.

But, how much sleep do we really need?

Here are recommendations from the National Sleep Foundation:

• Newborns (0 to 3 months old): 14 - 17 hrs
• Infants (4 months to 11 months old): 12 - 15 hrs
• Toddlers (1 to 2 years): 11- 14 hrs
• Preschoolers (3 to 5 years): 10 - 13 hrs
• School-aged children (6 to 13 years): 9 - 11 hrs
• Teenagers (14 to 17 years): 8 - 10 hrs
• Young adults (18-25 years): 7 - 9 hrs
• Adults (26-64 years): 7-9 hours
• Older adults (≥ 65 years): 7 to 8 hours