Definition: Psychological patterns that repeat approximately every 25 hours, such as the sleep-wakefulness cycle
Circadian comes from the Latin circa for "about" and dias for "a day".

Quite simply....

  • Is A 25-hour biological clock.
  • The natural schedule that the body makes for itself.
  • Your daily cycle of activities.
  • This routine goes for all living organisms, plants, insects, fungi, animals aquatic and land.


  • Circadian Rhythms
  • Waking up at an early hour on a Saturday morning because that's the time you wake up for school every day.
  • Getting hungry at about the same times every day.
  • The times you habitually get up, get ready for school, eat, and go to bed.

Disruptions to your circadian rhythms:
  • Flying through time zones may result in jet lag.
  • Daylight Savings Time.
  • After summer, trying to get your sleep back to "school schedule".
  • Sleeping in on the weekend, then coming back to your regular sleep schedule on school days.
  • Switching to the night shift at work.
  • Drinking coffee, energy drinks, or other caffeinated beverages and not going to sleep at your regular time.
  • Taking a random long nap in the middle of the day.

Additional Information

There was a tiny error that crept into the hard-wiring of teenage circadian rhythms, known as delayed sleep-phase syndrome. When puberty hits, the body clock seems to work differently, and control our entire life, causing harmful effects that adversely impact our bodies. The circadian rhythm in a human triggers the pineal gland, which is located at the base of the brain. Triggering this gland releases melatonin; a hormone that makes people drowsy as the evening winds down. The pineal gland slows it's production of melatonin in the morning, just in time for the person to wake up. During puberty, however, this cycle can be pushed back as long as two hours. Also when broken, it can be very hard to get into that rhythm. For example, when your parents get tired at ten, you're still wide awake and might not even begin to feel sleepy until midnight. And not falling asleep until midnight will make it all the more difficult to wake up at six. Teenagers can lose up to ten or more hours of sleep a week,


The chart on the left shows the average Melatonin levels in a person's body over the course of one day. The pineal gland begins producing Melatonin in the evening, as many people prepare for sleep. Melatonin levels peak in the middle of the night when most people are asleep, then fall back down to normal daytime amounts during the day when people are awake. The chart on the right shows the average Melatonin secretion over the course of an average person's life. Newborns tend to produce minimal melatonin; however, Melatonin peaks in early childhood. Once puberty hits, Melatonin secretion declines for the remainder of a person's life. Older people tend to produce a negligible amount of Melatonin.
Melotonin Day.jpg Melotonin Life.png

Additional Resources



  • Circadian rhythms is a physiological pattern that repeats every 24 hours. In the research an experiment explains the pronise of sleep of where sleep medicine explores the connections with health, happiness, and a good night's sleep. For an example of this in the research was when people ignore sleep an epidemic of heart disease, 33% of traffic-fatigue-related accidents, or immeasurable mental and psychological disadvantages are the many results of not having enough sleep in your cycle.Test were done in the experiment that offered a hands-on prescription for vibrant good health and longevity, which included a self-test to determine how much sleep you really need, the role of prescription and over-the-counter sleeping aids, the latest research on how sleep affects the immune system, how to combat with insomnia, snoring, and jet lag, and any information on sleep disorder clinics nationwide.These experiments were based on decades of studies on the frontiers of sleep science.