Heart palpitations are the physical manifestation of your heart being irregularly or skipping a beat. Some causes of heart palpitations are attributed to stress, exercise, or medication; in rare cases, heart palpitations signify a more serious condition like cardiac arrhythmia, thyroid problems, or anemia.

Awareness

In a normal state, a person should not be aware of the beating of their own heart. During heart palpitations, the person becomes conscious of this beating either because of the rapid nature or strength of each beat. The beat is often felt to resonate through the chest and even the throat area.

Missed Heartbeat

Most people, especially during the stage of consciousness described in section one, will also note a missed heartbeat. The heart feels like it's beating rapidly but will suddenly skip a beat or feel like a "flip" or "somersault" was performed inside the chest. In turn, some palpitations will record an extra beat rather than missing a beat.

Pounding Heartbeat

During a heart palpitation, it will feel like that muscles of the heart are contracting more aggressively than normal. Each beat will be strong and felt through the body as if the heart is beating with great effort and force.

Rapid Heartbeat

The heart will beat faster during a heart palpitation. The average rate of a healthy heart is 60-100 beats per minute; anything over is considered tachycardia. During a heart palpitations, tachycardia will occur, and beats as fast as 250-300 per minute have been recorded.

Warnings

Whichever of the above you experience occasionally, heart palpitations are usually situational and temporary. If you experience them regularly along with shortness of breath or lightheadedness, contact a medical professional to get assessed. While infrequent, heart palpitations can be indicative of a serious heart condition.

Source:

MayoClinic: Heart Palpitations

HealthLine: Heartbeats

National Institute of Health: Heart Health