Rapid Pulse
When the heart beats faster than normal
Quick Facts
- Type: Cardiovascular symptom
- Adult resting rate: Over 100 beats per minute is fast
- Common causes: Exercise, anxiety, fever, dehydration
- Seek urgent care: Chest pain, fainting, severe breathlessness
Overview
A rapid pulse means the heart is beating faster than normal. In adults, a resting heart rate over about 100 beats per minute is considered fast, a state doctors call tachycardia. A fast pulse is often a completely normal response to exercise, excitement, fear, or fever, when the body needs to pump more blood. The heart usually returns to its normal rate once the trigger passes.
At other times a persistently or unexpectedly rapid pulse signals that something needs attention, such as dehydration, an overactive thyroid, anemia, or a heart rhythm problem. Whether a fast pulse is harmless or concerning depends on how fast it is, how long it lasts, and what other symptoms come with it. Chest pain, fainting, or severe breathlessness with a racing heart are warning signs that need emergency care.
Common Causes
A rapid pulse can be a normal response or a sign of an underlying issue. Common causes include:
- Physical and emotional triggers: exercise, stress, anxiety, pain, caffeine, nicotine, or stimulants.
- Fever and infection: the heart speeds up with a raised temperature.
- Dehydration and blood loss: low fluid volume raises the heart rate. See dehydration.
- Anemia: fewer red blood cells make the heart work harder. See anemia.
- Overactive thyroid: excess thyroid hormone speeds the heart.
- Heart rhythm disorders: such as atrial fibrillation or other arrhythmias.
Associated Symptoms
Depending on the cause, a rapid pulse may come with:
- Palpitations or a pounding, fluttering heartbeat
- Shortness of breath
- Dizziness, lightheadedness, or fainting
- Chest pain or chest tightness
- Fatigue, sweating, or anxiety
- Symptoms of a trigger such as fever or excessive thirst
A rapid pulse together with chest pain, fainting, or severe breathlessness is a warning sign that needs emergency care.
Diagnosis & Evaluation
A clinician evaluates a rapid pulse by measuring the heart rate, checking the rhythm, and looking for a cause. Evaluation may include:
- Vital signs and history: heart rate, blood pressure, temperature, triggers, and other symptoms.
- ECG (electrocardiogram): a recording of the heart's electrical activity to check the rhythm.
- Heart monitoring: a wearable monitor for intermittent episodes.
- Blood tests: for anemia, thyroid function, infection, and electrolytes.
- Further tests: echocardiogram or other studies if a heart condition is suspected.
Treatment & Management
Treatment depends on the cause, and a fast pulse from a normal trigger often needs no treatment beyond addressing the trigger:
- Treating the cause: fluids for dehydration, treating fever or infection, correcting anemia, or managing thyroid disease.
- Lifestyle steps: reducing caffeine, nicotine, and stimulants, and managing stress.
- Rhythm control: medications or procedures for arrhythmias such as atrial fibrillation.
- Slowing techniques: certain maneuvers a clinician may recommend for specific fast rhythms.
- Emergency treatment: immediate care for dangerously fast rhythms or a rapid pulse with chest pain or collapse.
Many people with an occasional fast pulse from clear triggers are reassured after evaluation that no specific treatment is needed.
Self-Care & Prevention
You can lower the chance of an unwanted fast pulse with some simple habits:
- Limit caffeine, energy drinks, nicotine, and other stimulants that speed up the heart.
- Stay well hydrated, especially in hot weather or during exercise and illness.
- Practice stress-reduction techniques such as slow breathing, which can calm a racing heart from anxiety.
- Get regular, moderate exercise and enough sleep to support a healthy resting heart rate.
- Limit alcohol, which can trigger fast or irregular heartbeats in some people.
- Take any prescribed heart or thyroid medications as directed.
If you have episodes of a racing heart, note what brings them on and share this with your doctor, but never ignore a fast pulse that comes with chest pain, fainting, or severe breathlessness.
When to See a Doctor
See a doctor if you often have an unexplained rapid pulse, episodes that come on suddenly, or a fast pulse with other symptoms. Call emergency services right away if a rapid pulse comes with:
- Chest pain or pressure
- Severe shortness of breath
- Fainting, near-fainting, or severe dizziness
- A very fast heartbeat that will not slow down
A racing heart with chest pain, fainting, or severe breathlessness can signal a heart emergency and needs immediate care.
Frequently Asked Questions
What is considered a rapid pulse?
In adults, a resting heart rate above about 100 beats per minute is considered fast. A higher rate is normal during exercise, stress, or fever, but a persistently or unexpectedly fast resting pulse should be evaluated.
Is a rapid pulse dangerous?
Often it is a normal response to exertion, anxiety, fever, or caffeine and is harmless. It becomes concerning when it is unexplained, very fast, or comes with chest pain, fainting, or severe breathlessness, which need emergency care.
What can I do to slow a fast pulse?
If the cause is a trigger like caffeine, stress, or dehydration, removing the trigger, resting, and drinking fluids often help. Do not ignore a fast pulse with chest pain, fainting, or breathlessness, which needs urgent medical attention.
When should I call emergency services for a fast heartbeat?
Call emergency services if a rapid pulse comes with chest pain or pressure, severe shortness of breath, fainting, or a very fast heartbeat that will not slow down. These can signal a serious heart problem.
Can anxiety cause a rapid pulse?
Yes. Anxiety and stress trigger the body's fight-or-flight response, which speeds up the heart. The pulse usually settles as the anxiety eases, but recurrent or severe episodes are worth discussing with a clinician.
References
- American Heart Association. Tachycardia: Fast Heart Rate.
- Mayo Clinic. Tachycardia — Symptoms and causes.
- National Heart, Lung, and Blood Institute (NHLBI). Arrhythmias.
- MedlinePlus, U.S. National Library of Medicine. Rapid heartbeat.