6 symptoms of lack of sleep in children

6 symptoms of lack of sleep in children

The number of hours children sleep decreases every year—with consequences for their development.

1. Mood swings

Children who lack sleep are often impulsive, impatient and irritable (hello tantrum in the cereal aisle at the grocery store!).

While an adult who lacks sleep feels sluggish and drained of energy, children appear to have an excess of it when the night has been short.

Parents will notice a change in their child’s behaviour which inevitably has an impact on the parents’ mood.

2. Diminished concentration

When children lack sleep, they find it hard to pay attention and concentrate.

Other cognitive brain functions, such as reasoning, are compromised. Planning, problem-solving and decision-making all become more difficult.

And yet, it is during sleep that children assimilate all the information with which they have been bombarded in class.

With insufficient sleep, learning becomes more complex which, in turn, takes a toll on school performance.

3. Weight gain and obesity

Data from the Québec Longitudinal Study of Child Development (QLSCD) show that the risk of becoming overweight or obese is quadrupled in children aged between 2½ and 6 who sleep fewer than nine hours a day compared to young children who sleep eleven hours at night.

The phenomenon is similar to that of adults who suffer from insomnia.

Lack of sleep leads to hormonal changes, increasing the ghrelin level (the appetite-stimulating hormone) and reducing the leptin level (the fullness hormone).

4. Risk of depression and anxiety

Researchers have also measured the cortisol level—also called the stress hormone—and concluded that children who sleep less have higher cortisol levels.

This excessive stress might therefore explain the higher risk of depression and anxiety.

One thing is for sure: disrupted sleep and anxiety disorders can turn into a veritable vicious circle, with one having an adverse impact on the other.

5. Suppressed immune system

As we sleep, white blood cells release interleukin-1, a hormone that plays a crucial part in boosting the immune system.

Interleukin-1 helps defend the body against viral and bacterial infection and repair injury.

The immune systems of children who lose out on sleep over several consecutive nights will be weakened.

6. Injury and accident

Insomnia has an adverse effect on motor skills and concentration. If both are compromised, the risk of accidents and injuries is increased, says Dr. Carl Hunt of the National Center on Sleep Disorders Research in the United States.

It doesn’t take much to imagine the effect on a sleep-deprived teenager behind the wheel of a car.

Why is sleep so important?

Sleep is unquestionably one of the most popular scientific research topics.

Despite this, there’s still no easy answer to the question, “Why do we sleep?”

Among the theories is the one that tells us sleep allows the body to recover the energy spent during our waking hours.

On the other hand, we have more precise answers on the recommended daily sleep requirements.


Recommended hours of sleep per day

0-3 months

Between 14 and 17 hours

4-11 months

Between 12 and 15 hours

1-2 years

Between 11 and 14 hours

3-5 years

Between 10 and 13 hours

6-13 years

Between 9 and 11 hours

13-18 years

Between 8 and 10 hours

Ending sleep problems once and for all

Sleep problems are not incurable. Several steps can be taken to set up (and stick to) a healthy sleep routine when your child won’t sleep.