What happens when I wake up?

Several different body systems increase in order to have you awaken from sleep:
Your heart rate increases.
Your breathing becomes quicker and of greater volume.
Your circulation and blood flow increase.
Your brain produces different brainwaves.
Your eyes open and your body is more aware of external stimuli.
All of your organ systems (liver and kidney function, digestion, metabolism) increase back to “waking” values.
Your brain is flooded with hormones to decrease your arousal level so you are more likely to wake up and perceive stimuli.
Dr. Michael Roizen, MD
Internal Medicine
Complex changes occur in your body and mind as you awaken. Your melatonin levels have peaked, the stress hormone cortisol is on the rise, your body temperature has bottomed out, and your psyche is immersed in your dreams.

Increased levels of melatonin associated with deep sleep promote immune system activity, protect you from viruses, and have remarkable anticancer properties.
You: Staying Young: The Owner's Manual for Extending Your Warranty

More About this Book

You: Staying Young: The Owner's Manual for Extending Your Warranty

From the Authors of the #1 Bestselling YOU: On A Diet and YOU: On a WalkWouldn't you like to know how to prevent your body from aging badly? Most of us believe that at age 40 or so, we begin the slow...

Continue Learning about Sleep Basics

Tell Me Why…I Dream
Tell Me Why…I Dream
You’re in class and the teacher announces a surprise test. You haven’t studied, done homework or even been to class for weeks—and you may or may not b...
Read More
What are the health benefits of taking a nap?
Dr. Michael Roizen, MDDr. Michael Roizen, MD
In a world where 34% of employees work 41 to 60 hours a week and spend up to 80 hours a month co...
More Answers
What are the risks of sleep deprivation?
Dr. Christopher E. Morgan, MDDr. Christopher E. Morgan, MD
The risks of sleep deprivation may include: daytime sleepiness and fatigue decreased work produc...
More Answers
What's a Good Breathing Exercise to Help Me Sleep?
What's a Good Breathing Exercise to Help Me Sleep?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.