The close relationship between mental and physical health has long been suspected or understood by people. "Died of a broken heart" and "pined away from grief" are two phrases that describe this connection in its most extreme form. Many studies support this age-old intuitive understanding by demonstrating that in order to improve mental and physical wellbeing, healthy emotions must be felt and expressed in a suitably healthy way. Unhealthy emotions, or healthy emotions that are suppressed, can sap life's vitality and make people more prone to problematic coping strategies, long-term illnesses, or autoimmune symptoms. Although emotions have traditionally been categorized as either positive or negative, it may be more accurate to consider how they impact a person's overall perspective on life under a particular set of circumstances. Anger or terror, for example, might be a healthy reaction in some circumstances but uncalled for and, hence, harmful in others.
