Why do people get heart palpitations when they get upset?

Heart rhythm change: There are many different conditions that can cause the awareness of a different sensation - what we call palpitations. The vast majority of times in healthy people it is a benign condition - extra strong heartbeats due to the fight or flight response can be felt as a change and sometimes benign premature ventricular contractions due to adrenaline. If frequent or if other symptoms, see your doctor.

Neuroendocrine : Healthy patients' cardiovascular system is modulated by neurologic and endocrine factors. Young people are most responsive; they are healthy. The sickest patients (eg, diabetics) often show signs of having lost the neurologic input; their heart rate does not vary with emotional or physical stress.