Unexplained symptoms are worth exploring, but it's important to first speak to your GP and have potential medical causes appropriately investigated. This library is for information only and does not replace medical advice, diagnosis or testing.
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A rapid heart rate, known as tachycardia, occurs when the heart beats faster than usual. In adults, this generally refers to a resting heart rate above 100 beats per minute, although heart rate naturally varies with activity, emotions and individual circumstances.
Palpitations describe the sensation of being unusually aware of your heartbeat. This might feel like pounding, fluttering, racing, thumping or skipped beats.
Although rapid heart rate and palpitations often occur together, they aren't the same thing. Someone can experience palpitations with a normal heart rate, while another person may have a rapid heart rate without being particularly aware of it.
These sensations can occur during physical activity, emotional stress or periods of heightened nervous system activity. They can also happen unexpectedly, including when resting or lying down.
Rapid heart rate and palpitations are experienced across a range of conditions, including dysautonomia, Postural Orthostatic Tachycardia Syndrome (POTS), thyroid disorders, anaemia, cardiac arrhythmias and other health conditions.
For some people, episodes are brief and occasional. For others, they can be frequent, persistent or disruptive to everyday life.
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The heart has its own electrical system, which controls the timing and rhythm of each heartbeat.
Heart rate is also influenced by the autonomic nervous system, which regulates automatic bodily functions such as breathing, digestion, blood pressure and circulation.
The sympathetic nervous system: Helps prepare the body for action by increasing heart rate and supporting the circulation of blood to muscles and other tissues.
The parasympathetic nervous system: Helps regulate heart rate during quieter states, including rest and recovery.
These systems continuously adjust cardiovascular activity in response to the body's changing needs.
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When the brain perceives a threat, the sympathetic nervous system can activate the body's fight-or-flight response.
Stress hormones, including adrenaline, help prepare the body for action by increasing heart rate, changing breathing patterns and redirecting blood flow.
This response can occur during obvious moments of fear or anxiety, but it can also happen in response to ongoing stress, uncertainty or perceived danger.
For people experiencing prolonged stress or heightened alertness, heart rate changes and awareness of the heartbeat may become more noticeable.
The term survival mode is often used to describe this experience of persistent physiological readiness, although it is not a formal medical diagnosis.
Hypervigilance and Heartbeat Awareness
The brain continuously monitors signals from inside the body, a process known as interoception.
When someone becomes particularly alert to their heartbeat, ordinary fluctuations in heart rate or rhythm may feel more prominent.
For example, noticing a sudden heartbeat can trigger concern, which may increase adrenaline and make the heartbeat feel stronger or faster.
This can create a feedback loop between physical sensations, attention and the stress response.
Importantly, increased awareness of the heartbeat does not necessarily mean the heart is beating abnormally.
Emotions and the Body
Emotions influence cardiovascular activity through the autonomic nervous system.
Fear, excitement, anger, grief and anticipation can all produce noticeable changes in heart rate.
Some mind-body approaches also explore how emotional suppression, unresolved stress and longstanding patterns of heightened alertness may influence physical symptoms.
For example, someone who frequently suppresses anger or feels a persistent need to remain in control may experience physiological stress responses without consciously recognising an emotional trigger.
However, emotional suppression is not an established direct cause of tachycardia or cardiac arrhythmias. Stress-related processes are one possible influence among many.
Autonomic Dysfunction and Postural Changes
In some people, rapid heart rate is associated with changes in how the autonomic nervous system regulates circulation.
For example, in POTS, moving into an upright position produces an excessive increase in heart rate, often accompanied by dizziness, fatigue, weakness or brain fog.
This differs from a rapid heartbeat caused by emotional stress, although the sensations can overlap.
Other factors, including dehydration, fever, medications, hormonal changes and disturbances in heart rhythm, can also influence heart rate.
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Palpitations don't always mean your heart is beating faster.
Palpitations describe the sensation of your heartbeat. They can involve a normal rhythm, an unusually forceful beat, extra beats or changes in heart rate.
A racing heart isn't always caused by anxiety.
Heart rate can increase for many physiological reasons, including changes in posture, temperature, hydration, hormones and autonomic function.
Stress can influence heart rate without conscious anxiety.
The body's stress response can activate automatically, meaning someone may experience a racing or pounding heart without feeling frightened or worried.
Palpitations can feel different from person to person.
Some people notice fluttering in the chest, while others experience pounding in the throat, skipped beats or a sudden rush of rapid heartbeats.
Symptoms can be more noticeable at rest.
When lying quietly or trying to sleep, there may be fewer distractions from internal bodily sensations, making the heartbeat more noticeable.
Heart rate naturally changes throughout the day.
Movement, digestion, temperature, sleep, emotions and other factors all influence cardiovascular activity.
The sensation and the measured heart rate aren't always the same.
A heartbeat can feel unusually strong or rapid even when a wearable device or pulse measurement shows a rate within the normal range.
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Rapid heart rate and palpitations can be experienced in many different ways.
The sudden racing heart: Feeling the heartbeat accelerate unexpectedly, sometimes without an obvious trigger.
The pounding sensation: Becoming aware of strong heartbeats in the chest, neck, throat or ears.
The skipped beat: Experiencing a brief pause, flutter or unusually forceful beat.
The standing response: Noticing the heart racing after standing up, sometimes alongside dizziness or weakness.
The nighttime awareness: Becoming particularly conscious of the heartbeat when lying in bed or trying to fall asleep.
The adrenaline rush: Experiencing a sudden surge of physical activation, sometimes accompanied by trembling, warmth or a sense of urgency.
The invisible experience: Appearing calm externally while experiencing intense cardiovascular sensations.
For some people, these experiences are occasional and relatively mild. For others, they can affect sleep, concentration, physical activity, confidence and everyday functioning.
The frequency, duration and intensity of symptoms can vary considerably, including within the same person.
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Rapid heart rate and palpitations can have many causes, ranging from ordinary physiological responses to conditions affecting the heart, circulation or autonomic nervous system.
New, frequent, persistent or unexplained palpitations may warrant medical assessment, particularly when accompanied by dizziness, weakness or changes in exercise tolerance.
Palpitations or a rapid heartbeat accompanied by chest pain, severe breathlessness, fainting or significant deterioration can indicate a medical emergency.
