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Sleep in children
Last reviewed: 04.07.2025

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A child’s sleep is a natural component of his physiological activity, ensuring the normal rhythm of higher nervous activity processes, metabolic processes, physical development, growth and maturation.
Being a certain result of the preceding period of wakefulness, sleep, replacing this wakefulness, becomes a guarantee or condition for ensuring the normal life of the child in the subsequent wakefulness. It follows from this that inadequately organized wakefulness or illness of the child can lead to a violation of the completeness and effectiveness of sleep, and sleep disorders become the cause of insufficient activity of the child during wakefulness. Both can be the cause of a significant delay in the neuropsychic and physical development of children, and if preserved for a long time, leads to the occurrence of diseases. Therefore, monitoring the organization of the child's sleep, the characteristics of falling asleep, night sleep and awakening is an important component of general pediatric observation. Sleep disorders can be the basis for an in-depth examination of children.
A newborn baby's sleep is so-called polyphasic, i.e. it occurs many times during the day and night. Thus, during the day, a newborn baby falls asleep from 4 to 11 times, and the real differences between day and night in terms of sleep duration have not yet been established. Over the years, polyphasic sleep changes to monophasic, with only hidden elements of polyphasicity preserved in older children and adults.
A distinct predominance of night sleep occurs already at the end of the first month and stabilizes after that. In general, the natural need for sleep decreases with age.
Sleep needs in young children, h
Age |
Total per day |
At night |
During the day |
1 week |
16.5 |
8.5 |
8 |
1 month |
15.5 |
8.5 |
7 |
3 months |
15 |
9.5 |
5.5 |
6 months |
14.25 |
11 |
3.25 |
9 months |
14 |
11.25 |
2.75 |
12 months |
13.75 |
11.25 |
2.5 |
18 months |
13.5 |
11.25 |
2.25 |
2 years |
13.25 |
11 |
2.25 |
3 years |
12 |
10.5 |
1.5 |
4 years |
11.5 |
11.5 |
- |
5 years |
11 |
11 |
- |
6 years |
10.75 |
10.75 |
- |
7 years |
10.5 |
10.5 |
- |
8 years |
10.25 |
10.25 |
- |
9 years |
10 |
10 |
- |
10 years |
9.75 |
9.75 |
- |
11 years old |
9.5 |
9.5 |
- |
12 years old |
9.25 |
9.25 |
- |
13 years old |
9.25 |
9.25 |
- |
14 years old |
9 |
9 |
- |
15 years |
8.75 |
8.75 |
- |
16 years old |
8.5 |
8.5 |
- |
17 years old |
8.25 |
8.25 |
- |
18 years old |
8.25 |
8.25 |
- |
With a certain reduction in the total daily duration of sleep in children, this reduction occurs primarily due to the hours of daytime sleep. Already at the end of the first year of life, a child falls asleep during the day no more than 1-2 times. From 1 1/2-2 years, the duration of daytime sleep is about 2 1/2 hours, and about another hour is spent on falling asleep itself. After 4 years, not all children manage to maintain daytime sleep. Here, individual differences in the need for sleep have a significant impact. At the same time, it is desirable that daytime sleep be provided to all children up to 5-6 years of age.
A calm sleep of normal duration, short periods of transition from wakefulness to sleep, and vice versa (no more than 30 minutes), are evidence of the child’s health, normal lifestyle, and a good psychological climate in the family.
Electrophysiological onset of sleep in children
- disappearance of a-activity on the EEG and its replacement by low-voltage activity of mixed frequency;
- the appearance of slow eye movements on the electrooculogram;
- decreased muscle tone on electromyogram;
- generalized or local involuntary muscle contractions (electromyogram) - hypnotic myoclonus.
There are two qualitatively different phases of sleep:
- orthodox sleep, slow wave sleep phase (SRP);
- paradoxical sleep, rapid eye movement (REM) sleep phase.
It is believed that 3 groups of neurons are involved in the regulation of cyclic sleep phases.
Aminergic system (serotonergic + noradrenergic), or REM-off cells.
Cholinergic reticular system, or REM-on cells.
The individual phases and stages are best distinguished by their encephalographic characteristics:
- Stage I - drowsiness with gradual disappearance of the a-rhythm;
- Stage II - the appearance of encephalographic activity specific to this phase - sleep spindles, with a slowing of the pulse, a slowing of breathing, and muscle relaxation;
- Stages III and IV are stages of deeper sleep, characterized by the appearance of high-amplitude 8-activity and an increase in heart rate.
REM sleep phase in children
The REM sleep phase is characterized by a rapid desynchronized EEG, characteristic of intense wakefulness, although the child is in a state of deep sleep. At this stage, rapid eye movements, low skeletal muscle tone and the greatest instability of vegetative functions are noted - cardiac arrhythmia, up to short-term asystole, respiratory arrhythmia, and a drop in blood pressure. Active mental activity is also noted in the REM sleep phase - vivid dreams.
At all age stages, sleep is organized cyclically, i.e. successive stages of slow sleep end with a phase of rapid sleep. Several complete cycles are observed during the night.
Changes in the structure and duration of deep sleep can be determined by such a characteristic as the number of movements during sleep. In a child of the first years of life, it is greater than in older children (80 versus 60), but the abundance of movements during sleep does not interfere with the younger child's sleep and often leads to the awakening of the older child.
Physiological myoclonus is characteristic of the REM sleep phase - small rapid twitching of individual muscle bundles and groups with minor movement in small joints, such as twitching of fingers and facial muscles. In the stages of slow sleep, myoclonus is significantly less.
The first period of FBS is observed 70-100 minutes after the onset of sleep. The EEG pattern during this phase resembles that observed in stage I of FMS, but saw-tooth waves often appear on it.
The phases of slow and fast sleep alternate throughout the entire sleep period at intervals of 90-120 minutes. At the age of 2-3 years, the duration of one sleep cycle is about 60 minutes and the first episode of REM sleep is observed 1 hour after the child falls asleep. By the age of 4-5 years, the duration of the cycle can reach 90 minutes and during the entire sleep period about 7 cycles are recorded, which is almost identical to the sleep of an adult.
Slow wave sleep phase in a child
The slow-wave sleep phase becomes important in the overall sleep structure after 36 weeks of gestation, but has a very short duration. In a newborn child with normal gestation, FBS, FMS and undifferentiated sleep are identified. FBS can be recognized by sucking movements, almost continuous body movements, tremors, grimaces and even elements of cooing, irregular breathing, coinciding with bursts of muscle activity. FMS is distinguished by minimal motor activity and higher muscle tone.