“It is common to have multiple awakenings at night that are brief,” says Aarti Grover, MD, the medical director of sleep medicine at Tufts Medical Center in Boston. “You can have up to two to three short awakenings in most adults, which typically do not disrupt your sleep.”
People typically go through five full sleep cycles per night, with each lasting about 90 minutes, Dr. Grover explains. “During the first half of the night, slow-wave sleep, which is typically deep sleep, is prioritized,” she says. The latter half of the night involves more stage one (the lightest phase of sleep) and REM sleep, which is typically when we dream, Grover says.
“Transitioning into lighter sleep can lead to more awakenings with minor disruptions from a faint noise, temperature change, or subtle movements,” she adds.
Levels of the stress hormone cortisol may also play a role.
