Sleep has a distinct architecture with five key stages. Stages 1 and 2 are fairly light, while stages 3 and 4 (or delta wave) sleep are the deeper stages of sleep, followed by REM sleep.
Stages 1 and 2 are the non-restful sleep, the type of sleep where you toss and turn or wake up continuously during the night. With only this type of sleep, you will wake up tired and feel a lack of energy during the day.
Stages 3 and 4 (delta wave) sleep are the deeper stages of sleep. These are the recuperative stages, the sleep that produces growth hormone, which results in the repair and healing of your body.
Stage 5 is REM sleep. This is usually when you will dream. REM sleep will usually occur three to five times each night, each episode increasing in length as the night wears on.
Sleep is necessary or us to maintain our health in a variety of areas:
- Memory and learning
- Mood enhancement and social behavior
- Nervous system
- Immune system
- Growth and development
Without the deep, recuperative sleep that is necessary for good health, you can suffer from many undesired effects.
Studies have shown that sleep deprivation may be a associated with:
- Poor decision-making, poor judgment, increased risk-taking
- Poor performance in school, on the job, and in sports
- Impaired driving performance and increased risk of car accidents
- Increased incidence of obesity, diabetes, illness in general, high blood pressure, and heart disease
- Impaired memory, concentration, and ability to learn
- Physical impairment, poor coordination, delayed reaction time
- Anxiety, depression, and other emotional problems
- Magnification of the effects of alcohol on the body
- Exacerbation of the symptoms of ADHD, such as impulse control, irritability, and lack of concentration