Light and Heavy Sleep

All people go through different sleep cycles. We do, you do, and your baby does, too. Without going into great technical detail, we all go through periods of light and heavy sleep. In that respect, babies are no different than we are. What makes your baby’s sleep different from yours and mine is that your baby’s sleep cycles are shorter. Understanding her sleep cycles can help you to help your baby sleep longer.

In general, adults can go directly into a period of deep sleep from being awake. Young babies, however, go through a period of light sleep before they enter a deep sleep cycle. Ever parent has experienced this a time or two thousand. You think you’ve finally got junior to sleep, he appears to be sleeping soundly, but you try to lie him down, and he goes nuts and starts screaming bloody murder.

What’s happened is that baby is still in a light sleep cycle. Just like adults, when babies are in light sleep, they wake up easily. The difference is that babies spend a lot more time in light sleep than we do, mostly because they need to sleep lightly so they can cry out for us if they are hungry, wet, messy, hot, or otherwise uncomfortable.

In most cases, if you wait another fifteen or twenty minutes before lying baby down, she will sleep a lot longer. It’s not difficult to tell when baby reaches that point of deep sleep. Here are the signs:

  • Baby’s facial expressions won’t change during deep sleep. During light sleep, baby may grimace, frown, or even smile.
  • Baby’s muscles will relax and stay relaxed. During light sleep, baby may occasionally tense her muscles.
  • Baby will be still. During light sleep, baby may squirm a bit.
  • Baby’s breathing will be slow and regular. Babies in light sleep often have slightly irregular breathing.

Once baby is in a deep sleep state, she will usually stay that way for 45 minutes to an hour. Then you will notice her starting to move back into a light sleep phase. As long as she’s not hungry or uncomfortable, you can often help her sleep through the light sleep phase by singing softly to her, rubbing her back or legs gently, or otherwise soothing her.