Sleep is necessary for the body to reset after daily activities. The quantity of sleep (number of hours) is as important as the quality (deep and uninterrupted). The quantity of sleep needed per day, for proper body function, depends on the age of an individual, with children requiring more hours of sleep than adults.

How many hours of sleep is enough for a day?

There is no specific number of hours of sleep at night that guarantees being refreshed after waking up in the morning. However, there are basic guide / recommendations (based on age) on how many hours of sleep may be enough to make the body refreshed. These are as follows:

1. Newborns (0-3 months): 14-17 hours per day
2. Older infants (4-11 months): 12-15 hours per day
3. Children (1-5 years): 10-14 hours per day
4. Children (6-12 years): 9-11 hours per day
5. Teenagers (13-17 years): 8-10 hours per day
6. Adults (18-64): 7-9 hours per day
7. Elderly (65 years and above: 7-8 hours per day

The number of hours of sleep requirement per person per day decreases with age. Within these age groups, there is variation in the quantity of sleep required, as some people may need slightly more sleep while others may need slightly less. However, daily sleep hours too far below or above these recommended periods may lead to different health challenges such as obesity, hypertension, diabetes, depression or anxiety.

Why does sleep duration decline with age?

Several human activities cause disruption in sleep-wake cycle as we grow older. These activities constantly reset the sleep-wake cycle, thereby impacting on the duration of sleep per day. The production of sleep hormone (melatonin) also declines with age. These changes make adults have fewer hours of sleep, wake up earlier and more frequently than children.

What is quality of sleep?

This refers to how well you sleep at night, whether you sleep throughout without interruption or you wake up in-between; and the number of times you wake up before daybreak. It also involves how long it takes you to fall asleep again each time you wake up.

How to know if you had good sleep?

If you had good sleep, you would be refreshed and have full energy for the day when you wake up. On the other hand, if you had poor sleep, you might have daytime fatigue, sluggishness and clumsiness. Coordination of daily activities may be greatly impacted.

Why does sleep quality matter?

Sleep quality impacts significantly on health and quality of life, as people have poor sleep regularly are at higher risks of hypertension, diabetes, stroke, anxiety, depression etc.

How can sleep quality be improved upon?

The quality of sleep you have on a daily basis can be improved upon by:

1. Consistency: Having a fairly regular bedtime and regular time of waking up
2. Improved physical activity: Physical activities enhance blood flow to the body cells, thereby improving oxygen and nutrient supply. However, engaging in physical activities close to bedtime may delay you from falling asleep and, therefore, not encouraged.
3. Reduction in daytime nap: Prolonged daytime nap (more than 30 minutes) may deprive you of good sleep at night. Daytime nap should therefore be limited in order to enjoy good sleep at night.
4. Dinner at appropriate time: While eating too early may result in hunger before daybreak and disrupt sleep, eating too late may make the body too heavy and therefore cause discomfort and difficulty in initiating or maintaining sleep. For good sleep at night, dinner should be taken in moderate quantity and at the appropriate time (not earlier than four hours and not later than two hours before bedtime.