There may be a genetic predisposition to anxiety disorders; some sufferers report that a family member has or had a panic disorder or some other emotional disorder such as depression. The possibility of "genetic inheritance" of the disorder. Stressful life events can trigger panic disorders. Some researchers liken the "life stressor" to a thermostat; that is, when stresses lower your resistance, the underlying physical predisposition kicks in and triggers an attack. If a person with panic disorder experiences a racing heartbeat caused by drinking coffee, exercising, or taking a certain medication, they might interpret this as a symptom of an attack and, because of their anxiety, actually bring on the attack.