Sleep is not one continuous state—your brain and body move through several distinct stages each night. Understanding these stages can help you make sense of how restorative sleep supports memory, mood, and overall health.

Most people cycle through lighter sleep, deeper slow-wave sleep, and REM (dream) sleep multiple times. When those cycles are disrupted by disorders such as sleep apnea, you may wake feeling unrefreshed even after a full night in bed.

If snoring, gasping, or daytime fatigue sound familiar, a proper evaluation can identify whether an underlying sleep disorder is cutting your nights short.