1. Take the PTSD Quiz!
2. Stress-Reducing Foods Slideshow
3. Take the Panic Attacks Quiz!

Medical Author:

Maria Pease, MD

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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When you are afraid, your body activates the "fight or flight" response -- a reference to our caveman ancestors facing a tiger. In reaction, your body releases adrenaline, which is responsible for increasing blood pressure and heart rate and increasing glucose to muscles (to allow you to run away quickly in the face of immediate danger). However, once the immediate danger (which may or may not have actually existed) is gone, the body begins a process of shutting down the stress response, and this process involves the release of another hormone known as cortisol.

If your body does not generate enough cortisol to shut down the flight or stress reaction, you may continue to feel the stress effects of the adrenaline. Trauma victims who develop post-traumatic stress disorder often have higher levels of other stimulating hormones (catecholamines) under normal conditions in which the threat of trauma is not present as well as lower levels of cortisol. This combination of higher than normal arousal levels and lower than normal levels of the "calming" hormones of the changes creates the conditions for PTSD.

After a month in this heightened state with stress hormones elevated and cortisol levels lowered, you may develop further physical changes, such as heightened hearing. This cascade of physical changes, one triggering another, suggests that early intervention may be the key to heading off the effects of post-traumatic stress disorder.

The amygdala is the brain region that alerts the body to danger and activates hormonal systems.

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