Heart palpitations: causes, tests and when to worry

In short

• Palpitations are a racing, fluttering, pounding or irregular heartbeat, sometimes with skipped or extra beats.
• Common triggers are caffeine, alcohol, nicotine, stress, poor sleep, hard exercise and some medicines.
• Medical causes include iron deficiency anemia, an overactive thyroid and heart rhythm problems.
• Jot down when episodes happen and what you were doing, since the pattern helps your clinician.
• Palpitations with chest pain, shortness of breath or feeling faint need emergency care.

What palpitations feel like

The NHS describes palpitations as your heartbeat becoming more noticeable. You may feel a racing, fluttering or pounding heart, or an irregular beat with skipped or extra beats, in your chest, throat or neck. An episode can last seconds, minutes or longer.

The feeling and the actual heart rhythm do not always match. When you are anxious or focused on your body you may feel every beat, while a real rhythm problem can sometimes feel like very little. That is why recording what happens matters more than how dramatic it feels.

Causes and triggers

1. Everyday triggers.The NHS lists strenuous exercise, poor sleep, stress and anxiety, some medicines, and alcohol, caffeine, nicotine or recreational drugs. Menopause and pregnancy can also cause palpitations.
2. Things that strain the heart.The NHLBI adds dehydration, blood sugar that is too low or too high, low electrolytes such as potassium, magnesium or calcium, vomiting or coughing, and strong emotions such as anger, pain or a sudden surprise.
3. Medicines.Medicines that boost alertness or energy, and some over-the-counter allergy and cold medicines, can raise the heart rate. Tell your clinician about everything you take.
4. Medical causes.Iron deficiency anemia, an overactive thyroid, heart valve disease and arrhythmias can all be behind palpitations.
5. Arrhythmias.An arrhythmia is a problem with the rate or rhythm of the heartbeat, caused by changes in the heart's electrical signals. Some are harmless, but frequent irregular rhythms may mean the heart is not pumping enough blood.

How to track an episode

1. Sit down.Sit or lie down in case you feel light-headed.
2. Note the basics.Write down the time, how long it lasted, how it felt (racing, fluttering, skipping) and whether it seemed regular or irregular.
3. Record the context.Jot down what you had been doing, how you slept, how much caffeine or alcohol you had and any other symptoms such as dizziness or breathlessness.
4. Bring the log.Take your notes and a list of all medicines and supplements to your appointment. The NHLBI says your clinician will ask about your symptoms, lifestyle habits, and risk factors, so a log makes that conversation easier.

What you can do at home

If no health condition is behind your palpitations, the NHS says avoiding triggers such as stress, smoking, caffeine and alcohol can help. Staying hydrated and sleeping regularly are sensible, too, given that dehydration is on the NHLBI list of triggers.

Vagal maneuvers are relaxation techniques that may slow the heart rate. The NHLBI gives examples including coughing, bearing down while holding your breath (the Valsalva maneuver), lying down and placing an ice-cold wet towel over your face. They suit certain rhythm problems and not others, so ask your clinician whether and how to use them.

How a doctor finds the cause

• An electrocardiogram (ECG or EKG) records the heart's electrical activity using small pads on the skin. It is the most common test, but it only shows the rhythm during the recording.
• A Holter monitor is worn outside the body and records the rhythm during normal activities, usually for short periods.
• An implantable loop recorder sits under the skin for longer and can help explain palpitations or fainting that happen rarely.
• Blood tests measure substances such as potassium and other electrolytes, and thyroid hormone.
• Stress testing, imaging such as cardiac CT or MRI and, in selected cases, an electrophysiology study may follow if the first tests call for it.

You may be referred to a cardiologist for further tests.

Treatment in general terms

If a trigger is the cause, treatment is often just removing it. For arrhythmias, options described by the NHLBI include medicines for a fast or slow heartbeat, procedures such as cardioversion or catheter ablation, and devices such as pacemakers and implantable defibrillators, with the choice depending on the rhythm. Treating underlying problems such as thyroid disease, high blood pressure or sleep apnea may also help. All of this is decided by your clinician.

Red flags and when to see a doctor

Call 911 or go to an emergency department if palpitations do not go away, or if they come with chest pain, shortness of breath, or feeling faint. The NHS advises not driving yourself and bringing your medicines. Seek emergency care too for suspected heart attack.

Make a routine appointment with your primary care provider if you feel well but palpitations keep coming back or are happening more often, if episodes last more than a few minutes, or if you have a heart condition or a family history of heart problems. The NHLBI also notes that genetic testing can matter when close relatives have had an arrhythmia or cardiac arrest.

Questions to ask your clinician

• Could a medicine or supplement I take be causing this?
• Do I need a Holter monitor or another test to catch an episode?
• Should I be checked for thyroid problems or anemia?
• Which vagal maneuver, if any, is right for me?
• Which symptoms mean I should call 911 rather than wait for an appointment?

Questions and answers

Sources

1. NHS — Heart palpitations
2. MedlinePlus — Arrhythmia
3. NHLBI — Arrhythmias: Causes and Triggers
4. NHLBI — Arrhythmias: Diagnosis
5. NHLBI — Arrhythmias: Treatment

Sources checked on 29 October 2026.