I suggest discussing this matter with your doctor or psychologist to explore the stress, anxiety or other reasons you may be having the nightmare repeatedly. While you can find lots of information online about nightmares, it's best that you explore this topic with your doctor or counselor in person. A doctor or psychologist can help ensure that you receive accurate, evidence-based information, and provide advice specific to your individual health and well-being. Thanks for asking!
All nightmares are caused by palpitations. Persons who palpitation is easy to occur are easy to have nightmare, females are easier to have nightmare than males, because palpitation is easier occur to females than to males. Women have a huge amount of nightmares during pregnancy because women experience more palpitations in pregnancy. Physical factors that contribute to bad dreams include fever as also sleep because fever causes an increase in the heart rate, When palpitations occurs, people will have two most common feelings: one is tachycardia cause a feeling of seeming to be chasing ; the other is bradycardia or premature beat cause the feeling of heart suspension or heart sinking. Therefore, people in sleep accordingly will have the two most common nightmares : one is dream of being chased (occasionally hunting other people) ; the other is dream of flying in the air or dream of falling down.