Brief Answer: There are different causes of high heart rate and chest discomfort. You should do further examinations. Detailed Answer: Hello, Thank you for using HCM. High heart rate episodes, usually aren t serious or harmful, though, and often go away on their own. Most of the time, they re related to stress and anxiety or to consumption of stimulants such as caffeine etc. Even though, heart palpitations and chest discomfort may occur in specific medical conditions such as hyperthyroidism, or anemia, low blood pressure, dehydration, abnormal electrolyte levels etc. In rare cases, palpitations can be a sign of a more serious heart condition. A laboratory assessment of the thyroid hormones levels (TSH, fT3, fT4) should be done to exclude a hyperthyroidism. If it will be proven by the results of the above mentioned levels of the thyroid hormones, you should see an endocrinologist for further treatment strategy and follow-up. Electrolyte levels assessment (Na, K, Cl, Ca) is essential, too and their correction (if deviations are noted) is necessary. Anemia can be ruled out by making a full blood count exam. If anemia is proven, you should treat it and your chest discomfort and will go away. To be very careful, you should make an ECG and a stress test. You should take a Holter ECG which registers your heart rate during the period you keep it. The results should be discussed with the cardiologist. If all the above mentioned exams are normal, than stress and anxiety remain the most probable causing factor of your symptoms. Meanwhile you should take plenty of water (2 - 3 liters per day). You should take an equilibrated diet. Try to avoid getting stressed or anxious. Hope this is helpful. Let me know if you need more clarifications. Otherwise please close and rate the answer. Kind Regards, Dr. Juarda