National Sleep Foundation

Chapter 1: Normal Sleep

The Physiology of Sleep

Sleep influences all of the body’s major physiologic systems, including thermoregulatory, musculoskeletal, endocrine, respiratory, cardiovascular, gastrointestinal, and immune systems. Sleep also impacts individual’s weight, mental health, and overall quality of life.

All of these relationships are bi-directional: in other words, many of these physiologic systems also influence an individual’s sleep. Partial or total lack of sleep, disturbed sleep, and poor quality sleep can all drastically change an individual’s thinking and behavior and negatively impact his or her physical, mental, and emotional health.