could be one of a number of aging-associated diseases). As an indirect or non-determinative factor, biological aging is the biggest contributor to deaths worldwide. It is estimated that of the roughly 150,000 people who die each day across the globe, about two thirds—100,000 per day—die of age-related causes. In industrialized nations the proportion is much higher, reaching 90%. In recent years, there have been official claims about a possibility of recognizing aging itself as a disease. If this would be so, the situation would change. Emotional death There are also popular notions that someone can be "scared to death" or die of loneliness or heartbreak. Experiencing fear, extreme stress, or both can cause changes in the body that can, in turn, lead to death. For example, it is possible that overstimulation of the vagus nerve—which decreases heart rate in a mechanism related to the behavior of apparent death (also known as "playing dead" and "playing possum")—is the cause of documented cases of psychogenic death. The flight or fight response to fear or stress has the opposite effect, increasing heart rate through stress hormones, and can cause cardiovascular problems (especially in those with pre-existing conditions). This is the proposed mechanism for the observed increase in the death rate due to cardiac arrest after widely experienced acutely stressful events such as terrorism, military attacks, and natural disasters (even among those who are not in the affected area) and for documented deaths in muggings and other frightening events which caused no traumatic physical harm. The proximal medical cause of death in these cases is likely to be recorded as cardiac failure or vagal inhibition (which also has other potential causes such as blows to certain parts of the body and nerve injuries). One specific condition observed to result from acute stress, takotsubo cardiomyopathy, is nicknamed "broken heart syndrome", but the stress need not be relationship-related and need not be negative. See also Death by misadventure List of causes of death by rate List of preventable causes of death References Epidemiology Legal terminology Medical terminology Statistical data coding Vital statistics (government records)