The vast majority of heart palpitations are not life threatening. People who suffer from heart palpitations describe them as feeling their heart skip a beat and then feel their heart pound in their chest or as periods of a really fast heartbeat or irregular heartbeats for a period of time. While most palpitations are harmless, they can be very troublesome for the person suffering from them.There are several causes for heart palpitations, both medical and non-medical.Medical Causes for PalpitationsCardiac arrhythmia � almost everyone who is suffering from heart palpitations has some sort of cardiac arrhythmia or irregular heart beat. Almost any type of arrhythmia can cause palpitations. The most common arrhythmia associated with heart palpitations is PVC's or premature ventricular complexes, PAC's or premature atrial complexes, SVT or supraventricular tachycardia or atrial fibrillation.Sometimes heart palpitations can be the result of a dangerous cardiac arrhythmia. Life-threatening arrhythmias that can cause heart palpitations include ventricular tachycardia or v-tach. Most often when someone is suffering from a life threatening arrhythmia it's because there is some sort of Heart disease.Identifying the reason for the heart palpitations is especially important for persons who are also suffering from some sort of heart disease. It is equally important to find the cause for heart palpitations in patients who are at an increased risk of developing heart disease.Non-medical Causes for PalpitationsStress or anxiety � Someone suffering from panic attacks or anxiety attacks will frequently complain of feeling their heart pound in their chest. This pounding is a heart palpitation and can get worse with increased stress and/or anxiety.Exercise � Engaging in strenuous exercise will sometimes cause heart palpitations. This is because you have pushed your body to the point of exhaustion.Caffeine � Found in most soda and energy drinks, caffeine is a known stimulant. Some people are more sensitive to caffeine and other stimulants and this can cause heart palpitations.Nicotine � Nicotine is found in cigarettes and smokeless tobacco. People, especially those who are not used to using nicotine, will experience heart palpitations when first exposed to nicotine.Hormones � Changes in hormone levels such as the changes associated with pregnancy, menstruation and menopause will sometimes induce heart palpitations.Pseudoephedrine � Cough and cold medications that contain pseudoephedrine can sometimes cause palpitations. Pseudoephedrine is a stimulant medication.Inhalers � Medications that are inhaled, such as those to treat acute Asthma symptoms, can be a cause of heart palpitations. These medications are known as rescue inhalers and contain stimulant medication that works to open the airways. The medication in these inhalers can also cause heart palpitations.In addition to the over the counter and prescription medications listed above, some illegal drugs can cause heart palpitations. Drugs that are stimulants such as cocaine and methamphetamines cause palpitations.There are many different causes for heart palpitations both medical and non-medical. While palpitations can be bothersome and increase anxiety it's good to know that most palpitations are not life-threatening. If palpitations increase or are accompanied by other symptoms it's advisable for you to visit your personal physician.