Why Zebras Don't Get Ulcers: A Guide to Stress, Stress Related Diseases, and Coping

Allostasis is an expanded view of homeostasis, which occurs when the body is physically balanced. This definition is important for understanding the concepts of stressors and stress-response: Stressors remove the body from allostasis, and the stress-response reestablishes allostasis.

Analgesia refers to an inability to sense pain. Analgesia occurs through a rise in opioid or opiate chemicals. It can occur as a natural phenomenon, such as when a wounded soldier does not feel their injury or, more commonly, when someone runs long enough to experience a “runner’s high.” Analgesia can also arise from artificial circumstances, such as through opiate medications or acupuncture, which trigger a release of natural opioids. Hyperalgesia occurs when the emotional perception of pain is intensified, such as when a person with a fear of needles is hypersensitive to vaccinations.

Anxiety disorders are a group of mental health disorders associated with fear, vigilance, and insecurity. Subtypes of anxiety include generalized anxiety disorder, phobias, obsessive-compulsive disorder, and post-traumatic stress disorder. Symptoms of anxiety may include panic attacks, hyperventilation, ritualized behavior, and vigilance.