What is Sleep?

Sleep is the body’s natural rest cycle. The recommended hours of sleep for an adult are 6-8 hours, whereas children can require 8-10 hours (11-14hours for infants).

Sleep occurs in repeating periods, alternating between two distinct stages- NREM (non-rapid-eye-movement) and REM (rapid-eye-movement) sleep. NREM comprises 75-80% of our sleep, whereas REM comprises 20-25% of sleep. An average night’s sleep lasts for 6-8 hours, alternating between NREM and REM sleep in 90-110minute cycles. A normal sleep pattern will have 4-5 of these cycles a night.

Sleep is important for our survival. Animal studies have demonstrated death can occur from chronic sleep deprivation. Many biological processes occur during sleep to help us grow and function normally during the day.

Some of the biological processes that occur during sleep are:

• Energy conservation
• Physical growth and development
• Thermoregulation
• Metabolic processes
• Hormone regulation and secretion
• Wound healing
• Immune system maintenance
• Memory consolidation
• Neural growth
• Information processing

During sleep, it is important the body spends enough time in each of the NREM and REM sleep cycles. Inability to sustain optimal NREM and REM sleep can lead to impairment in any of the above biological processes, and ultimately, sleep deprivation.

Negative Affect Of Sleep Deprivation

Sleep deprivation is when the body is not having sufficient quality and/or quantity of sleep. Poor sleep can adversely affect the brain and cognitive function. This can lead to:

• Chronic pain and increased sensitivity to pain
• Inability for the body to heal
• Increased risk for illness/disease
• Irritability
• Difficulty modulating impulses and emotions
• Mood swings
• Poor concentration and attention
• Poor memory and forgetfulness
• Inability to learn and/or process new information
• Decreased coordination
• Decreased physical performance
• Increased weight gain/loss
• Paradoxically, in some cases it can lead to increased energy, alertness and enhanced mood (e.g. ADHD)