Hello, Thumbing or pounding sensation that you are experiencing is because the heart rate is faster than your system can take. It can be due to your age, level of fitness, anxiety, stress, fatigue, appropriate rest or inadequate sleep. It indicates that you need a healthier lifestyle, start caring for yourself more than before. The medical conditions that can cause such symptoms are arrythmia, atrial fibrillation, supraventricular tachycardia (SVT), developing cardiovascular disease or rheumatic fever, etc. You are suggested to get clinically examined by a cardiologist, get all routine cardiac tests, blood workouts & imaging tests done. You will be treated according to the pathology detected. In the meantime, avoid stimulants, stay away from any type of stress and anxiety, take ORS to restore electrolyte balance, drink water, take adequate and relax. Cut on carbs, sugars, refined floor, oily junk food, fried food and addictions if any. Rest is one of the basic factors that helps reduce palpitations or arrhythmia naturally. Get treated at the earliest. Do regular exercises, maintain healthy weight & take boiled food or food cooked in olive oil. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician