Palpitations
Palpitation is a perceived abnormality of the heartbeat characterized by awareness of heart muscle contractions in the chest: hard beats, fast beats, irregular beats, and/or pauses. It is both a symptom reported by the patient and a medical diagnosis. Palpitation is frequently associated with anxiety and does not necessarily indicate a structural or functional abnormality of the heart, but it can be a symptom arising from an objectively rapid or irregular heartbeat. Palpitation can be intermittent and of variable frequency and duration, or continuous. Associated symptoms include dizziness, shortness of breath, sweating, headaches, and chest pain.
Palpitation may be associated with coronary heart disease, hyperthyroidism, diseases affecting cardiac muscle such as hypertrophic cardiomyopathy, diseases causing low blood oxygen such as asthma and emphysema; kidney disease; low levels of brain serotonin; blood loss, and pain; drugs such as antidepressants, alcohol, nicotine, caffeine, cocaine, and amphetamines; electrolyte imbalances of magnesium, potassium and calcium; and deficiencies of nutrients such as taurine, arginine, and iron.