palpitation
The feeling of your heart beating very hard or fast.
Palpitation is the sensation of your heart beating unusually hard, fast, or irregularly in your chest. When you experience palpitations, you become very aware of your heartbeat in a way you normally aren't. It might feel like your heart is pounding, fluttering, or skipping beats.
Palpitations often happen during moments of intense emotion or physical exertion. If you've just sprinted across the playground or climbed several flights of stairs quickly, you might feel your heart thumping forcefully. Strong feelings can trigger them too: nervousness before presenting in front of your class, excitement while waiting for test results, or fear during a scary movie might all cause your heart to race noticeably.
Most palpitations are harmless and temporary, a natural response to adrenaline or exercise. Your heart usually returns to its normal, barely noticeable rhythm once you calm down or rest. However, if someone experiences frequent palpitations without an obvious cause, or if they come with dizziness or chest pain, that person should see a doctor to make sure everything's working properly.