Signs You May Not Be Getting Enough REM or Deep Sleep

The article explains differences among light, deep and REM sleep and reports that adults typically need about 1.5 to 2 hours of deep sleep while REM usually begins around 90 minutes after falling asleep.

Humans sleep in cycles that are broadly divided into non-REM and REM stages. Light sleep includes stages 1 and 2 and serves as the transition into deeper rest, with stage 2 linked to memory consolidation. Deep sleep usually occurs in the first half of the night and is associated with physical recovery and growth-hormone release. REM sleep generally appears about 90 minutes after falling asleep and is tied to dreaming and emotional and memory processing. Key points: - Light sleep (stages 1 and 2) is the initial transition and stage 2 shows bursts of brain activity that research links to transferring short-term memories into longer-term storage. - Deep sleep involves cellular repair and growth-hormone secretion, occurs in longer segments early in the night, and is when heart rate and breathing are at their lowest. - Adults typically need about 1.5 to 2 hours of deep sleep per night, and insufficient deep sleep can leave a person feeling tired despite a full night of rest. - REM sleep starts roughly 90 minutes after sleep onset, features rapid eye movements and irregular breathing, and is when most dreaming occurs; during REM, limb muscles are temporarily paralyzed by brain chemicals. - The article notes that some people track sleep stages to compare how they feel with their sleep architecture, while others prefer to sleep without trackers. Summary: Deep sleep and REM sleep serve distinct roles: deep sleep supports physical recovery while REM sleep is important for dreaming and memory and emotional processing. The article reports typical timing and amounts for these stages and mentions that comparing sleep-stage data with personal feelings is one way people use sleep information. Undetermined at this time.