Did you know that as we age, we need less and less sleep?  When you are 65 years old, you will likely not require the same amount of sleep you needed when you were 20. A typical newborn sleeps between 14-17 hours per day, with 2-3 of these hours in the form of daytime naps.  

As all of you parents have probably experienced, sleep deprivation can make you and your little one cranky!   

I get lots of parents in my family medicine practice asking about how much sleep their little one needs.  It is important to make sure your little one is not sleep deprived. In this article I talk about how and why sleep needs change over our lifetime, and the research that shows exactly how much sleep your little one will need at different ages.  

How much sleep do I need?

As all you mamas have probably experienced, sleep deprivation can make us irritable, tired, and cranky.  Our sleep needs actually increase with more physical work and exercise, during medical illnesses, mental stress, and during pregnancy!  Normal people require between 6-9 hours of sleep per night, but you might need a little bit more if you are sick, pregnant, or under a lot of stress. As we age, we also need less and less sleep.  When you are 65 years old, you will likely not require sleeping the same amount of time as you did when you were 20. Some research studies have suggested this is in part due to a process known as “calcification” of the pineal gland – a gland that helps regulate our sleep hormones.

For babies, toddlers, preschoolers, and adolescents – their sleep needs change throughout lifetime. The national sleep foundation has established guidelines for how much babies, toddlers, adolescents, and adults should sleep.

These are the suggested total sleep times (including nap time) for children between 0 and 16 years old:

• Newborn Sleep (0-3 months): 14-17 hours each day
• Infants Sleep (4-11 months): 12-15 hours each day
• Toddlers Sleep (1-2 years): 11-14 hours each day
• Preschoolers Sleep (3-5): 10-13 hours each day
• School age children Sleep (6-13): 9-11 hours each day
• Teenagers Sleep (14-17): 8-10 hours each day
• Younger adults Sleep (18-25): 7-9 hours each day
• Adults Sleep (26-64): 7-9 hours each day
• Older adults (65+): 7-8 hours each day

Children from 0 – 4 years old will often have sleep that is divided between night time sleep, and day time napping.  Newborns will often nap up to 3 hours per day, meaning that of the 14-17 hours of sleep they require each day, 3 of those hours will occur throughout the day in the form of naps.

So how much sleep does your toddler need?  I thought it was best to answer this question by exploring what is the average nap time for toddlers.

Based on a study of 493 healthy children enrolled in a Swiss study – these were the average nap times for children between 0 and 5 years old:

• Newborn Sleep 0-6 months: 2-3 hours of napping
• 6 months – 1 year: 2 and a half hours of napping
• 12 months – 18 months: 2 hours and 15 min of napping
• 18 months – 24 months: 2 hours of napping
• 2 – 3 years old: 1 hour and 45 minutes of napping
• 4 years old: 1 hour and 30 minutes of napping
• 5 years old: this is when most children start to forgo their daytime nap.  The average sleep time at this age is 11 hours with no naps.

How does napping change as my child gets older?

As your child gets older, they will need less and less time to nap throughout the day.  At the age of 1 year, the average child will nap 2 and a half hours per day.  By 2 years old, they will on average nap 2 hours per day.  At 4 years old, their naps will be reduced to 1.5 hours per day.  By the age of 5 years old is when most children forgo their napping, and can obtain most or all of their sleep at night.

So what exactly is sleep?

Sleep is an incredibly important part of our natural biology.  It involves important chemicals known as neurotransmitters (namely serotonin, norepinephrine, acetylcholine, dopamine, and melatonin).  The parts of the brain that are particularly involved in sleep include the brainstem (which helps regulate wakefulness), the pineal gland (which regulates melatonin production), and the Suprachiasmatic nucleus (which helps regulate our circadian rhythms).

Sleep is composed of 2 main types – REM and non-REM sleep. REM (Rapid Eye Movement or dreaming sleep, which is important for memory consolidation) and Stage 1, Stage 2, Stage 3 (also known as deep sleep and is very important for growth and development in children as Growth Hormone is released here).  Stage 1-3 are collectively known as non-REM sleep.  Most healthy adults will have 4-5 “episodes” of REM sleep throughout the night, with stages 1-3 also occurring throughout our sleep cycles, with stage 3 occurring mostly in the first half of the night.

So what are the different stages of sleep and what do they mean?

• Stage 1 of sleep is kind-of similar to those experiences you have nodding off in a super boring lecture.
• Stage 2 of sleep is the majority of our sleep (around 50%) this is your light stage of sleep.
• Stages 3 of sleep are our “restful” or deep stages of sleep.  In normal healthy adults, these start 30-40 minutes after we begin sleeping.  Most of our restful sleep actually occurs in the first 3-4 hours we begin sleeping!
• REM sleep: this starts about 90 minutes after sleep onset, and continues episodically throughout the night.  During this stage, our heart rates, blood pressure, and breathing rates change.  Our brains are quite active during this phase, and this is where dreaming occurs.  Most of our REM sleep happens in the last 3 or so hours of sleep.

The patterns of our sleep change over the lifetime, depending on our age, our health, and any medical illnesses or medications we take.