Restless sleep in infants

Restless sleep in infants: What movements and sounds during sleep mean

Parents often imagine an infant's sleep as quiet and carefree. So when they see their child moving arms and legs, frowning, smiling, grunting, or even whimpering in their sleep, it causes concern. However, in most cases, such "restless" sleep is completely normal and even vital for the child's development. It is a manifestation of the so-called active sleep phase, which dominates in infants.

Two sleep phases: Active and quiet

Human sleep consists of cycles that include two main phases:

• Active sleep (REM sleep): This is the phase when the brain is highly active— it processes the information gathered during the day, forms neural connections and "sees" dreams. In adults this phase accounts for about 20-25% of total sleep. In infants — up to 50%! It is during this phase that a baby may move, make sounds, and its eyes under closed eyelids move rapidly.
• Quiet sleep (NREM sleep): This is the deep sleep phase, when the body is maximally relaxed, breathing is even, and the brain rests. It is much harder to wake a baby during this phase.

Since infants spend half of their sleep in the active phase, it is not surprising that their sleep appears restless. This is not a sign of discomfort, but evidence of intensive brain activity. Every parent should know about sleep physiology.

When can restless sleep be a sign of a problem?

Although physiological restlessness is normal, sometimes movements during sleep can be caused by discomfort.

• Physical discomfort: Gas, reflux, itching from eczema or pain from teething can cause the baby to twist and wake up.
• Neurological features: In rare cases, excessive and stereotyped movements may require a neurologist consultation.
• Skill practice: Often infants who have recently learned to roll over or crawl continue to "practice" in their sleep, leading to awakenings.