Feeling your heart race, flutter or skip while also struggling to catch your breath can be frightening. Sometimes the cause is temporary and relatively harmless, but this combination can also occur with arrhythmias, heart or lung disease, anemia and other medical conditions.
Heart palpitations and shortness of breath can occur together when the heart is beating too fast, too slowly or irregularly, because an abnormal rhythm can reduce how efficiently the heart pumps blood. However, the same combination may also occur with anemia, heart failure, pulmonary embolism, asthma or other lung disease, thyroid problems, fever, dehydration, stimulant use, exercise, pregnancy or anxiety. Mild brief symptoms still deserve attention if they keep returning. Severe or sudden breathlessness, particularly with chest pain, fainting, severe dizziness or a sustained rapid or irregular heartbeat, needs urgent medical assessment.
When Palpitations and Shortness of Breath May Be an Emergency
Seek urgent or emergency medical care if heart palpitations occur with:
- severe or rapidly worsening shortness of breath;
- shortness of breath while sitting still or resting;
- significant chest pain, pressure, squeezing or tightness;
- fainting or loss of consciousness;
- collapse;
- severe dizziness or a feeling that you are about to faint;
- a sustained very rapid or markedly irregular heartbeat while feeling unwell;
- bluish or gray lips or skin;
- confusion or severe weakness; or
- other rapidly worsening symptoms.
Do not assume severe breathlessness is simply anxiety, especially when it is new, unexplained or accompanied by other cardiovascular warning signs.
What Does It Mean to Have Palpitations and Shortness of Breath Together?
A heart palpitation is the sensation of being unusually aware of your heartbeat.
You may describe your heart as:
- racing;
- fluttering;
- pounding;
- thumping;
- skipping beats; or
- beating irregularly.
Shortness of breath — also called dyspnea — means feeling that breathing is difficult, uncomfortable or insufficient for what your body needs.
When the two symptoms occur together, they may share one cause or may result from two separate problems happening at the same time.
A person with anxiety, anemia, atrial fibrillation and pulmonary embolism could all describe “racing heart and shortness of breath.” The timing, heart rhythm, oxygen level, examination and other tests help distinguish these very different conditions.
See our main guide to heart palpitation symptoms for the different ways palpitations may feel.
Why Can an Abnormal Heart Rhythm Make You Short of Breath?
The heart and lungs work together to deliver oxygen-rich blood to the body.
When the heart beats very quickly, very slowly or irregularly, the chambers may not fill and pump blood as efficiently as they normally do.
In some people, this reduction in effective blood flow can produce:
- shortness of breath;
- fatigue;
- weakness;
- lightheadedness;
- reduced exercise tolerance; or
- fainting in more severe cases.
The severity depends on the type of rhythm, its speed, how long it lasts, heart function and the person’s underlying health.
Important Point: Palpitations Are a Symptom, Not a Rhythm Diagnosis
Feeling your heart race or flutter does not tell us whether the rhythm is sinus tachycardia, atrial fibrillation, SVT, premature beats or even a normal rhythm that has become unusually noticeable.
Recording the electrical rhythm during the episode is often the most useful way to establish whether an arrhythmia is responsible.
What Can Cause Heart Palpitations and Shortness of Breath?
There are several important possibilities.
Atrial fibrillation
AF can cause a rapid and irregular heartbeat, fluttering or thumping, shortness of breath, weakness, dizziness and reduced exercise tolerance.
Some people have few symptoms, while others notice a dramatic change in how their heart and breathing feel.
Supraventricular tachycardia
SVT can cause the heart to suddenly accelerate, often producing a rapid regular palpitation. Shortness of breath, dizziness or weakness may accompany the episode.
PACs and PVCs
Premature atrial or ventricular contractions can feel like skipped beats, pauses or forceful thumps.
Most isolated premature beats are not dangerous, but frequent ectopy can sometimes be associated with shortness of breath and deserves evaluation when symptoms are persistent.
Sinus tachycardia
The heart’s normal pacemaker can speed up appropriately during exercise, fever, dehydration, pain or emotional stress.
In this situation, the faster pulse and breathlessness may both reflect the body’s response to an underlying physical demand.
Heart failure
When the heart cannot pump as effectively as it should, shortness of breath may develop during activity, while lying flat or sometimes at rest. Some patients also notice a racing or throbbing heartbeat.
Anemia
Anemia reduces the blood’s ability to carry oxygen. The body may compensate by increasing heart rate, causing palpitations together with breathlessness, fatigue, weakness or dizziness.
Thyroid disease
Excess thyroid hormone can accelerate the heart and may contribute to atrial fibrillation or other rhythm symptoms.
Tremor, heat intolerance, sweating and weight changes may provide additional clues.
Lung disease
Asthma, COPD, pneumonia and other pulmonary conditions can cause breathlessness. Low oxygen levels or the physical effort of breathing may also make the heart beat faster.
Pulmonary embolism
A blood clot blocking an artery in the lung can cause sudden unexplained shortness of breath, a rapid or irregular heart rate, chest pain, dizziness or fainting.
This can be life-threatening and requires urgent medical evaluation.
Anxiety or panic
Anxiety can cause rapid breathing, a racing heart, chest tightness and an intense awareness of the heartbeat.
However, new palpitations with breathlessness should not automatically be labeled as anxiety before relevant heart, lung and medical causes have been considered.
Medicines and stimulants
Caffeine, nicotine, energy drinks, pseudoephedrine, some asthma medicines, ADHD medicines and recreational stimulants may increase heart rate or produce palpitations in susceptible people.
Pregnancy and hormonal changes
Pregnancy normally increases cardiovascular demand and can make both heart rate and breathing more noticeable. However, anemia, thyroid disease, arrhythmia or other conditions may need consideration when symptoms are significant.
For a broader overview, see causes of heart palpitations .
Could It Be a Pulmonary Embolism?
Pulmonary embolism deserves specific attention because it can produce both a rapid heartbeat and sudden breathlessness.
Possible warning features include:
- sudden or unexplained shortness of breath;
- chest pain that becomes worse with a deep breath or coughing;
- rapid or irregular heartbeat;
- dizziness, lightheadedness or fainting;
- coughing blood;
- low oxygen levels;
- one-sided leg swelling or calf/thigh pain; and
- recent surgery, prolonged immobility or another important blood-clot risk factor.
Suspected Pulmonary Embolism Requires Urgent Medical Care
Sudden unexplained breathlessness together with chest pain, fainting, coughing blood, marked weakness or a rapid heartbeat should not be watched at home while waiting to see if the symptoms pass.
Could Heart Failure Cause Both Symptoms?
Yes. Heart failure does not mean the heart has stopped. It means the heart is not pumping as effectively as the body requires.
Symptoms may include:
- shortness of breath with normal activities;
- shortness of breath while lying flat;
- waking from sleep breathless;
- fatigue;
- leg or ankle swelling;
- rapid weight gain from fluid retention;
- persistent cough; and
- a racing or throbbing heartbeat.
New or worsening shortness of breath in a person with known heart failure should be reported promptly to the treating clinician.
Does the Timing of the Symptoms Give Any Clues?
Timing cannot make a diagnosis, but certain patterns can help guide medical evaluation.
If the episodes occur during physical activity, see heart palpitations after exercise .
How Do Doctors Evaluate Palpitations With Shortness of Breath?
Evaluation begins by deciding how urgent the situation is and whether the symptoms are more likely to originate from the heart, lungs, blood or another medical condition.
Medical history
Your clinician may ask:
- when the symptoms started;
- whether they began suddenly or gradually;
- how long episodes last;
- whether the heartbeat feels regular or irregular;
- whether symptoms occur at rest or during activity;
- whether breathing is worse when lying down;
- whether chest pain, fainting, dizziness or weakness occurs;
- whether one leg has recently become swollen or painful;
- about caffeine, alcohol, nicotine and medications;
- about pregnancy, recent surgery or prolonged travel/immobility;
- whether there is known heart or lung disease; and
- whether there is a family history of serious rhythm or heart disease.
Vital signs and oxygen level
Heart rate, blood pressure, respiratory rate, oxygen saturation and temperature can provide important clues, particularly when shortness of breath is present.
12-lead ECG
An electrocardiogram can identify atrial fibrillation, flutter, tachycardia, bradycardia, conduction abnormalities and other electrical findings.
If the symptoms are happening during the ECG, the test may immediately reveal the rhythm causing the palpitation.
If the palpitations stop before the ECG is recorded, a Holter, patch or event monitor may be needed to capture the rhythm during an actual episode.
Blood tests
Depending on the clinical picture, tests may include:
- a complete blood count to look for anemia;
- thyroid testing;
- electrolytes;
- kidney function;
- other blood tests directed by the symptoms; and
- cardiac biomarkers when acute heart injury is suspected.
Echocardiogram
Echocardiography can evaluate heart structure, pumping function, valves and other findings when heart failure, structural heart disease or certain arrhythmias are suspected.
Chest and lung testing
A chest X-ray, pulmonary testing or other imaging may be appropriate when lung disease, infection, fluid accumulation or another respiratory condition is possible.
Testing for pulmonary embolism
When the clinical picture raises concern for a pulmonary embolism, clinicians may use a combination of risk assessment, blood testing such as D-dimer and imaging such as CT pulmonary angiography.
Testing should be based on clinical probability rather than performed routinely for every person with palpitations.
Exercise testing
When symptoms are consistently brought on by exertion, exercise testing or rhythm monitoring during physical activity may be considered.
How Are Heart Palpitations and Shortness of Breath Treated?
There is no single treatment because these are symptoms, not one disease.
If an arrhythmia is responsible
Treatment depends on the rhythm and may include:
- observation;
- medication;
- cardioversion in selected situations;
- catheter ablation;
- a pacemaker for specific slow-rhythm disorders; or
- other rhythm-specific treatment.
Atrial fibrillation may also require assessment of stroke risk and whether anticoagulation is appropriate.
If anemia is responsible
The cause of the anemia needs to be identified. Treatment depends on whether the problem is iron deficiency, blood loss, vitamin deficiency, chronic disease or another condition.
If heart failure is responsible
Management may involve medications, fluid and sodium guidance, treatment of the underlying cardiac disease and careful monitoring.
If lung disease is responsible
Asthma, COPD, infection and other respiratory conditions each require their own treatment plan.
If anxiety contributes
Stress management, appropriate psychological treatment, sleep improvement and reduction of excessive stimulants may help when anxiety is genuinely contributing.
However, anxiety treatment should not replace cardiac or respiratory evaluation when symptoms are new or concerning.
Do Not Treat the Symptom Combination With a Heart Medicine on Your Own
Beta-blockers, calcium-channel blockers, antiarrhythmic medicines, diuretics and blood thinners have specific indications and risks.
Treatment should follow the diagnosis rather than trying to slow an unknown heartbeat simply because palpitations and breathlessness occurred together.
Dr. Albana’s Note
When a patient tells me, “My heart starts racing and then I cannot get enough air,” I want to know exactly which symptom came first, how suddenly the episode began, what the pulse felt like and whether there was chest discomfort, dizziness, weakness or fainting. I also ask whether it happened during exercise, while resting or while lying down. Anxiety can certainly cause both symptoms, but I do not assume anxiety when someone has a new combination of palpitations and breathlessness. An ECG, basic blood tests and sometimes longer rhythm monitoring can help us find out what is really happening.
When Should You Make a Medical Appointment?
Arrange medical assessment if:
- palpitations and breathlessness keep returning;
- episodes are becoming more frequent;
- palpitations last for minutes rather than isolated seconds;
- the heartbeat feels persistently fast or irregular;
- you become short of breath with activities that were previously easy;
- breathing becomes uncomfortable when lying flat;
- you repeatedly wake during the night short of breath;
- you have new ankle or leg swelling;
- you have unusual fatigue, weakness or dizziness;
- symptoms repeatedly occur during exercise;
- you have known heart or lung disease; or
- the symptoms are affecting your normal activities or quality of life.
If dizziness accompanies the episodes, see dizziness and heart palpitations .
If unusual weakness is prominent, see heart palpitations and weakness .
Urgent Warning Signs
Seek urgent or emergency medical care for palpitations with:
- severe or sudden shortness of breath;
- shortness of breath at rest that is new or worsening;
- chest pain, pressure or tightness;
- fainting or loss of consciousness;
- collapse;
- severe dizziness or near-fainting;
- a sustained very rapid or markedly irregular heartbeat;
- bluish or gray lips or skin;
- coughing blood;
- sudden breathlessness with one-sided leg swelling or pain;
- confusion, severe weakness or signs of shock; or
- rapidly worsening symptoms.
These symptoms can occur with serious arrhythmias, heart attack, pulmonary embolism, acute heart failure or other urgent conditions.
If chest pain accompanies the episode, see our chest pain and heart palpitations guide for additional education, but seek emergency care first when warning signs are present.
Most Asked Questions
Are heart palpitations and shortness of breath dangerous?
Not always. The combination can occur with anxiety, exercise, anemia or other treatable conditions, but it can also occur with arrhythmias, heart failure, pulmonary embolism or other serious problems. New, recurrent or worsening symptoms should be medically evaluated.
Why do heart palpitations make me feel short of breath?
A rapid or irregular rhythm may reduce how efficiently the heart fills and pumps blood. This can produce breathlessness, weakness or dizziness. However, the two symptoms can also come from a separate condition such as anemia, lung disease or anxiety.
Can atrial fibrillation cause palpitations and shortness of breath?
Yes. Atrial fibrillation may cause a rapid irregular heartbeat, fluttering or thumping in the chest, shortness of breath, weakness, dizziness and reduced exercise tolerance. Some people with AF have few or no symptoms.
Can anxiety cause palpitations and trouble breathing?
Yes. Anxiety and panic can increase heart rate, produce rapid breathing and create a sensation of not getting enough air. However, new or persistent symptoms should not automatically be attributed to anxiety before other relevant causes are considered.
Can anemia cause a racing heart and shortness of breath?
Yes. Anemia reduces oxygen-carrying capacity, so the heart may beat faster in an attempt to maintain oxygen delivery. Fatigue, weakness, dizziness or pale skin may also occur.
Can dehydration cause palpitations and shortness of breath?
Significant dehydration can produce a faster heart rate and weakness, particularly after vomiting, diarrhea, fever, heat exposure or heavy sweating. Severe or persistent breathlessness should not automatically be blamed on dehydration.
Can PVCs make you short of breath?
Some people with premature ventricular contractions report both palpitations and shortness of breath. Occasional PVCs are often benign, but frequent or symptomatic PVCs may require ECG monitoring and, in selected patients, evaluation of heart structure and function.
Why do I get palpitations and breathlessness when walking upstairs?
Possibilities include normal exertional responses, poor conditioning, anemia, asthma, heart failure, lung disease or an exercise-triggered arrhythmia. A new decline in exercise tolerance deserves medical assessment.
Can a pulmonary embolism cause a racing heart and shortness of breath?
Yes. Pulmonary embolism can cause sudden unexplained shortness of breath, rapid or irregular heart rate, chest pain, dizziness or fainting. Coughing blood or one-sided leg swelling may also occur. Suspected PE requires urgent medical care.
Can a normal ECG rule out the cause?
Not always. A standard ECG records only a short period. If your symptoms come and go, a Holter, patch or event monitor may be needed to record the heart rhythm during an episode.
When should I go to the emergency room?
Seek emergency care for severe or sudden shortness of breath, chest pain or pressure, fainting, severe dizziness, collapse, coughing blood, signs of shock or a sustained very rapid or markedly irregular heartbeat while feeling seriously unwell.
Related Heart Palpitation Guides
Medical References
- American Heart Association. How Serious Are Heart Palpitations? Causes, Symptoms and When to Worry. Published February 9, 2026. American Heart Association .
- American Heart Association. Symptoms, Diagnosis and Monitoring of Arrhythmia. Last reviewed October 10, 2024. American Heart Association .
- American Heart Association. What Are the Symptoms of Atrial Fibrillation? Updated 2025. American Heart Association .
- American Heart Association. Pulmonary Embolism. Updated 2026. American Heart Association .
- American Heart Association. Heart Failure Signs and Symptoms. Last reviewed May 29, 2025. American Heart Association .
- Mayo Clinic. Heart Palpitations: Symptoms and Causes. Mayo Clinic .
- Mayo Clinic. Heart Palpitations: Diagnosis and Treatment. Mayo Clinic .
- Mayo Clinic. Shortness of Breath: Causes. Updated 2025. Mayo Clinic .
- American Heart Association. Premature Contractions — PACs and PVCs. Last reviewed September 24, 2024. American Heart Association .
About the Medical Team
Dr. Albana Greca, MBBS, MMedSc
Family Physician / General Practitioner
Dr. Albana Greca has more than 20 years of experience in primary care, general medicine, chronic disease management, prevention, patient education and digital health.
Dr. Benard Shehu, MBBS, MS
Cardiologist
Dr. Benard Shehu has more than 19 years of cardiovascular experience, including clinical experience relevant to arrhythmias and cardiovascular disease.