False pregnancy False pregnancy False pregnancy, also known as phantom, hysterical pregnancy, pregnancy scares or pseudocyesis, is the appearance of clinical or subclinical signs and symptoms associated with pregnancy when the person is not actually pregnant. False pregnancy may sometimes be purely psychological. It is generally believed that false pregnancy is caused by changes in the endocrine system of the body, leading to the secretion of hormones that cause physical changes similar to those during pregnancy. Some men experience the same illnesses as a woman would experience while pregnant when their partner is pregnant (see Couvade syndrome), possibly caused by pheromones that
Fight-or-flight response Fight-or-flight response The fight-or-flight response (also called hyperarousal, or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first described by Walter Bradford Cannon. His theory states that animals react to threats with a general discharge of the sympathetic nervous system, preparing the animal for fighting or fleeing. More specifically, the adrenal medulla produces a hormonal cascade that results in the secretion of catecholamines, especially norepinephrine and epinephrine. The hormones estrogen, testosterone, and cortisol, as well as the neurotransmitters dopamine and serotonin, also affect how