How much sleep do I need?

The amount of sleep a person needs to have each night to keep them alert and restore their body differs hugely with their age. 

Infants have an overall greater total sleep time than any other age group. A newborn's total sleep duration in one day is usually between 14 and 16 hours, although this is broken into many short sleeps. 

Over the first 6 months or so of life, infants' sleep requirements change substantially, and by the fifth or sixth month of life most infants will have one main sleep at night and a shorter sleep period during the day.

Pre-adolescent children require about 9 hours of sleep overall, whereas most teenagers and young adults require at least ten hours for full physical replenishment. It should be noted that recent studies have found that not only do teenagers require more sleep than adults or younger children, they require it at different times of the day. There is evidence that the natural time for a teenager or young adult to begin sleeping is much later than at any other point in their life, at 11pm or later. 

Adults seem to need about 8 to eight and a half hours of sleep per night.

I don't get that much sleep, but I feel fine.

Perhaps you are fine. But perhaps you are just fooling yourself. 

The Epworth Sleepiness Scale was designed for people to test themselves to see whether they might be suffering from sleep deprivation. Give each activity a score based on how likely you would be to doze during it.

0 = Would never doze 
1 = Slight chance of dozing 
2 = Moderate chance of dozing 
3 = High chance of dozing

A score of greater than 10 is a definite cause for concern as it indicates significant excessive daytime sleepiness. 

What happens if I don't get enough sleep?

Our sleep patterns are set by an internal clock referred to as a circadian clock, which regulates body temperature, hormone levels, heart rate and other vital body functions. When a person suffers from chronic sleep deprivation, these functions soon become impaired. A person in this state is also likely to have their mood, memory and concentration levels affected. 

Some of the effects of sleep deprivation are:

With decreased sleep, higher-order cognitive tasks are affected early and disproportionately. Tests requiring both speed and accuracy demonstrate considerably slowed speed before accuracy begins to fail. 

Why does it happen?

Of course, the most common cause of sleep deprivation is simply not sleeping enough due to being too busy or  having your sleep interrupted,  particularly for parents of infants, shift workers and people who travel a lot.

Some of the other causes of sleep deprivation are?

What can I do about it?

If you are suffering from sleep deprivation, try to rearrange your schedule to allow you a little more sleep. Ensure your sleeping place is a restful one with a comfortable mattress, good air circulation and protection from unwanted light and noise.

If practicable, have a short sleep during the afternoon (between 2pm and 6pm is best, as the body is at a naturally low ebb during this time).