Sleep Deprived TeenagersOn average, high school teens need nine to twelve hours of sleep for their bodies to function properly. The body undergoes four phases of sleep. “Stage 1 of sleep, the lightest stage, is the transition from wakefulness to deeper sleep. Stage 2, middle sleep, accounts for 40-50% of your sleep time. Stages 3 and 4, called slow-wave or delta sleep, are the deepest levels and occur primarily in the first third of the night. Most high school students only reach third or fourth grade three times a night, which is the most vital. At this point, the student's body slowly repairs itself (Karriem-Norwood). These results of lack of sleep caught the attention of Dr. Mary A. Carskadon of Brown University who did an experiment on the effects of sleep on the body, which revealed that the students' bodies became accustomed to the circumstances in which they were involved. Health expert Denise Dador said: “Experts say about 80 percent of high school students are sleep deprived. They are biologically programmed to stay up late” (Dador). Even though most high school students' bodies have evolved, side effects have appeared. Students experience increased stress in their lives due to the pressure to complete assignments; high blood pressure can also result from the same stress problem. Research has also found that lack of sleep in students leads to decreased learning and memory, since their minds are focused on sleep. A high school freshman says, “If I sleep less than four hours, I have a much harder time staying focused, which makes it difficult to pay attention in class and do well on homework” (quoted in Taylor )Dr. Kohler, a pediatric sleep expert, says the...... middle of document ......eep Deprived » Center For Advanced Health. January 2010. Web. April 1. 2014. Enayati, Amanda. “Does Homework Make Your Child Sick?” CNN.com. March 21. 2014. Web April 1. 2014. “Excessive Homework and Sleep Deprivation” Teen Ink. March. 2011. Internet. March 31. 2014. “Getting Enough Sleep Will Help You Boost Your Test Scores – AASM for Teens” MNT. January 8, 2008. The web. April 1. 2014. Karriem-Norwood, Varnada. “Common Sleep Disorders in Adolescents” WebMD. March 17. 2013. The web. April 1. 2014. “Benefits of Napping: 6 Reasons to Take a Nap on National Nap Day” True Entertainment Magazine. March 12. 2013. Internet. April 1. 2014. “Homework Research Spotlight” National Education Association. Nd Web. April 1. 2014. Taylor, Hannah. “Sleep deprivation and its effects on the brain” Daily Emerald. October 28, 2013. The web. April 1. 2014. Weber, Trisha. “Connect” with Evansville business. Can. 2012. Internet. April 1. 2014.