Definition - What does delta wave mean?
Delta waves are slow brain wave frequencies that generally arise during deep sleep, generated from the thalamus. Delta waves occur in stages 3 and 4 of the sleep cycle, prior to REM sleep. Delta waves are important to overall health and well-being, and are crucial to the experience of being rested, despite the hours spent asleep.
SureHire explains delta wave
All brain waves are measured using an electroencephalogram (EEG), with the delta brain wave measuring between 0-4 Hz. Delta brain waves are associated with the body's restorative function, increasing the strength of the immune system and production of the hormone HGH (Human Growth Hormone), which is responsible for healing the body. Lack of deep sleep and delta brain waves is associated with an increase in cortisol, the stress hormone, impaired memory and compromised ability to perform. Drugs and alcohol can have long-term effects on the delta-wave activity in the brain, and women tend to have more delta wave activity than men.