Occasional heart palpitations or changes in heart rate shouldn’t be cause for alarm. But if they’re happening frequently, you might want to make an appointment with your health care provider to determine if there is an underlying medical problem. Thyroid issues, low blood sugar, and low blood pressure all can cause your heart to race. If you experience dizziness, chest pain, fainting, or shortness of breath, seek medical help immediately. These could be signs of a more serious problem.