Circadian Rhythm Directory
Circadian rhythm disorders are disruptions in a person's circadian rhythm -- a name given to the "internal body clock" that regulates the (approximately) 24-hour cycle of biological processes in animals and plants. Circadian rhythms are important in determining human sleeping patterns. When your body clock gets off schedule -- as can occur when traveling, working the night shift, or taking certain medications -- problems may develop that affect sleep. Follow the links below to find WebMD's comprehensive coverage about circadian rhythm disorder, what causes it, how to treat it, and much more.
Testing for Circadian Rhythm Disorder
WebMD explains tests used to pinpoint sleep problems.
Non-24-Hour Sleep-Wake Disorder
The causes, symptoms, diagnosis, and treatment of non-24-hour sleep-wake-disorder (Non-24), a condition that disrupts your ability to go to sleep at night and stay awake during the day.
Understanding the Side Effects of Sleeping Pills
WebMD takes a look at the side effects of popular sleeping pills. Here's what you need to know to sleep soundly and safely.
Basics on Sleep
WebMD explains the stages of sleep -- REM and non-REM -- and how age affects these cycles.
10 Ways to Reset Your Sleep Cycle
Are jet lag, night shifts, or insomnia dragging you down? Learn how to reset your sleep clock for better, more restful sleep.
Daytime Tips to Get a Better Night's Sleep
Find out what you can do during the daytime to help you sleep better at night.
Surviving Night Shift Sleep Problems and Health Effects
WebMD explains what shift work sleep disorder is and how you can maintain a healthy life and get the sleep you need while working late shift hours.
Better Sleep Tips for Business Trips
Business travel and sleep do mix; they have to, or you will be far less productive than you may think.
Adjust for Daylight Saving Time
You’ve adjusted your clock to daylight saving time, but have you adjusted your body?
Helping the Blind Re-set Their Body Clocks
For those who are blind, their body clocks tend to drift which can be devastating.
Daylight Savings Time and Sleep
Why are so many of us disoriented by the time change each year? Get tips on adjusting more quickly.
Are You a Night Owl?
Learn how to fall asleep before your second wind kicks in.
Slideshows & Images
A Visual Guide to Sleep Disorders
Pictures show you the symptoms, causes, tests, and treatments for sleep problems.
What to Do Today to Sleep Better Tonight
See how to get better sleep with tips about diet, exercise, scheduling, and more.
Can't Sleep? It Could Be What You're Eating
Could a good night’s sleep come down to your diet? Discover which foods hinder sleep and which foods promote restful slumber.
12 Causes of Fatigue and How to Fight It
Always tired? WebMD examines causes and fixes for fatigue.
The Science of Sleep
The Science of Sleep. What happens in your brain and body while you slumber? Find out in this quiz.
Why You Need Your ZZZs Quiz
Take this quiz and test your knowledge of sleep -- deprivation, insomnia, and nightmares.
What's Wrecking Your Sleep?
Quiz: What's Wrecking Your Sleep? Stress, alcohol, and illness can keep you up. Find out what else might ruin your rest in this quiz.