- Short sleep duration of less than 5 hours a day increases the risk for high Blood pressure by 350% to 500% compared to those who slept longer than 6 hours per night.
- Young people in the age group of 25 to 49 years are twice as likely to get high Blood Pressure if they sleep less.
- Individuals who slept less than 5 hours a night had a 3-fold increased risk of heart attacks. The reason for the same is complete and partial lack of sleep increased the blood concentrations of High sensitivity C-Reactive Protein (hs-cRP), the strongest predictor of heart attacks.
- Just one night of sleep loss increases number of toxic substances in body such as Interleukin- 6 (IL-6), Tumour Necrosis Factor-Alpha (TNF-alpha) and C-reactive protein (cRP). They increase risks of many medical conditions, including cancer, arthritis and heart disease.
Sleep is composed of two stages: REM ( Rapid Eye Movement ) and non-REM. The former helps in mental consolidation while the latter helps in physical repair and rebuilding. During the night, you alternate between REM and non-REM stages 4-5 times.
The earlier part of sleep is mostly non-REM. During non-REM sleep, many of the restorative functions of sleep occur. Hormones are released which help the body rebuild itself from damage done during the day. During REM sleep, memories and thoughts from the day are processed. REM sleep is the stage of sleep in which vivid dreams occur. The purpose of dreaming is not well understood, but it probably relates to processing mental information that was received during the day. During REM sleep, we normally lose the use of our limb muscles. Thus, we have an active mind in an inactive body. This normal loss of muscle activity in REM (or dream) sleep helps prevent us from acting out our dreams. For you to be mentally alert during the day, the latter part of sleep is more important.