A behind-the-scenes look at the science of stress; the effect of stress on human bodies; how the human response to stress is different than that of a zebra being hunted along a savannah.

Every time one has a thought or emotion, things change in their body; the two factors responsible for these changes are the nervous system and hormones; how these systems work; how they are regulated; what happens to them during moments of stress..

Armed with the necessary background information, exploring how specific organ systems suffer when faced with chronic stress; how long-term stress can damage heart muscles, inflame and clog blood vessels and also lead to sudden cardiac arrest.

The next organ system to focus on is the metabolic system; cycles of chronic stress lead to a persistent activating and storing of energy; this can lead to an inefficient use of energy; a critical role in the prevalence of adult-onset diabetes.

The role stress plays in one's gastrointestinal tracts; knowing why most people eat more during stressful periods; how stress affects bowel disorders like irritable bowel syndrome; stress combines with a bacterial infection to produce ulcers.

Stress and child development; studying prenatal and postnatal life; Professor Sapolsky reveals the ways a fetus can respond to the environmental stressors of its mother; how different parenting styles can affect the stress levels of young children.