Atrial fibrillation (AFib) is a common heart rhythm disorder in which the heart beats irregularly and may beat faster than normal. Some people experience a racing heartbeat, fluttering in the chest, dizziness, or shortness of breath, while others have no noticeable symptoms. Although AFib can sometimes go undetected, it is important to diagnose and manage it because it can increase the risk of blood clots, stroke, and heart failure.
Understanding the symptoms, causes, diagnosis, and treatment options can help you recognise when to seek medical attention and make informed decisions about your heart health.
What Is Atrial Fibrillation (AFib)?
Atrial fibrillation, also called AF or AFib, is an abnormal heart rhythm known as an arrhythmia. It occurs when the electrical signals in the heart’s upper chambers, called the atria, become disorganised. Instead of contracting in a coordinated way, the atria quiver or fibrillate, causing the heartbeat to become irregular and sometimes unusually fast.
In a healthy heart, electrical signals coordinate the contractions of the upper and lower chambers, allowing blood to circulate efficiently. During AFib, the disorganised signals interfere with this coordination, and the lower chambers may beat irregularly.
This can affect how efficiently the heart pumps blood. Blood may also remain in parts of the atria for longer than normal, increasing the possibility of clot formation.
Why does this matter? A blood clot can travel through the bloodstream to the brain and block blood flow, causing an ischaemic stroke. AFib can also contribute to heart failure, particularly when the heart rate remains poorly controlled.
Not everyone with AFib feels unwell. Some people discover the condition during a routine examination or after an ECG is performed for another reason. The absence of symptoms does not mean that the condition is harmless.
What Does Atrial Fibrillation Feel Like?
People often describe AFib as a fluttering, racing, pounding, or irregular heartbeat. Others notice that they become tired more easily or feel breathless during ordinary activities.
The experience can vary considerably. Some people have short episodes that come and go, while others have a persistent irregular heartbeat. A person may also have AFib without noticing any symptoms.
If you experience repeated episodes of an irregular heartbeat, unexplained dizziness, or unusual breathlessness, arrange a medical assessment rather than assuming the symptoms are caused by stress or anxiety.
When is AFib a medical emergency?
Seek emergency medical help if you experience chest pain or pressure, severe difficulty breathing, fainting, or symptoms that suggest a stroke, such as sudden facial drooping, weakness in one arm, difficulty speaking, or sudden vision or balance changes. Do not drive yourself to hospital. If stroke symptoms occur, get help even if they disappear.
In India, call 112 or your local ambulance service, such as 108 where available.
What Are the Symptoms of Atrial Fibrillation?
AFib symptoms can range from barely noticeable to severe enough to interfere with daily activities. The most common symptoms include the following.
1. Irregular or rapid heartbeat
You may feel that your heart is racing, pounding, fluttering, skipping beats, or beating unevenly. These sensations are known as palpitations and can occur at rest or during activity.
2. Shortness of breath
Some people experience breathlessness while walking, climbing stairs, exercising, or even resting. This may happen because the irregular rhythm reduces the efficiency of the heart’s pumping action.
3. Fatigue and weakness
AFib can make everyday tasks feel unusually tiring. You may notice reduced stamina, difficulty completing routine activities, or persistent weakness without an obvious explanation.
4. Dizziness or lightheadedness
An irregular or fast heartbeat can affect blood flow and contribute to dizziness, lightheadedness, or a feeling that you might faint.
5. Reduced exercise tolerance
Activities that previously felt comfortable may become more difficult. For example, you might need to stop more frequently while walking because of tiredness, palpitations, or breathlessness.
6. Chest discomfort
Some people experience chest discomfort, tightness, or pressure. New or significant chest pain requires emergency assessment, because it may indicate a heart attack or another serious problem rather than AFib alone.
7. No noticeable symptoms
AFib can occur without obvious warning signs. This is one reason that an irregular pulse found during a health check should not be ignored. An ECG can help determine whether AFib is present. American Heart Association+2
What Causes Atrial Fibrillation?
AFib develops when abnormal electrical activity disrupts the heart’s normal rhythm. It may occur because of changes in the heart’s electrical system, underlying heart disease, other medical conditions, or a combination of factors.
In some people, no single cause can be identified.
Common conditions and factors associated with AFib include the following. American Heart Association+1
1. High blood pressure
Long-standing or poorly controlled high blood pressure places additional strain on the heart. Over time, this can cause structural changes that make an irregular rhythm more likely.
2. Coronary artery disease
Coronary artery disease reduces blood flow to the heart muscle and can contribute to changes that affect the heart’s electrical activity.
3. Heart valve disease
Problems involving the heart valves, particularly the mitral valve, can place extra pressure or volume stress on the atria and increase the likelihood of AFib.
4. Heart failure and other heart conditions
Changes in the heart’s structure or pumping function can increase the risk of developing AFib. The relationship also works in the other direction: poorly controlled AFib can worsen heart failure.
5. Thyroid disorders
An overactive thyroid gland, known as hyperthyroidism, can increase the heart rate and trigger abnormal heart rhythms, including AFib.
6. Diabetes
Diabetes is associated with a higher risk of cardiovascular disease and AFib. Managing blood glucose and other cardiovascular risk factors is an important part of long-term heart health.
7. Obesity and sleep apnoea
Excess body weight and obstructive sleep apnoea are associated with an increased risk of AFib. Sleep apnoea causes repeated interruptions in breathing during sleep and can place stress on the cardiovascular system.
8. Alcohol consumption and smoking
Alcohol, particularly excessive or heavy consumption, can trigger episodes in some people and contribute to long-term risk. Smoking also harms cardiovascular health and is an avoidable risk factor.
9. Age and family history
AFib becomes more common with age, although younger adults can develop it too. A family history of AFib may also increase susceptibility.
10. Recent heart surgery or other acute illness
AFib can occur after heart surgery. In some people, acute illness or other physiological stressors may also contribute to an episode.
Important: Having one or more risk factors does not mean that you will definitely develop AFib. Similarly, AFib can occur in people who do not have any obvious risk factors. American Heart Association+1
What Can Trigger an AFib Episode?
A cause or underlying risk factor is not always the same as a trigger. A trigger may temporarily make an episode more likely in someone who is susceptible to AFib.
Possible triggers include:
- Excessive alcohol consumption.
- Significant sleep deprivation.
- Dehydration or acute illness.
- Intense physical or emotional stress in some individuals.
- Certain stimulant-containing products or medications.
- Uncontrolled thyroid disease or other medical conditions.
Triggers vary from person to person, and not every episode has an identifiable cause. Caffeine affects people differently, so it is not necessary for everyone with AFib to avoid it completely. If you notice a consistent relationship between a particular drink, product, activity, or medication and your symptoms, discuss it with your healthcare professional before making significant changes.
What Are the Different Types of Atrial Fibrillation?
Doctors classify AFib according to how long the irregular rhythm lasts and whether it stops on its own or requires treatment.
1. Paroxysmal atrial fibrillation
Episodes start and stop intermittently. They usually end within seven days, often much sooner, either spontaneously or with treatment. Symptoms may be occasional or frequent.
2. Persistent atrial fibrillation
The irregular rhythm continues for more than seven days. Medical treatment is generally needed if restoring a normal rhythm is the chosen approach.
3. Long-standing persistent atrial fibrillation
AFib has continued for more than 12 months. A rhythm-control approach may still be considered in selected patients.
4. Permanent atrial fibrillation
The patient and treating clinician have decided not to pursue further attempts to restore a normal rhythm. Treatment still focuses on appropriate heart-rate control, stroke prevention, and symptom management.
These categories describe the rhythm’s pattern and duration, not necessarily how severe the patient’s symptoms are. Even intermittent AFib can carry a risk of stroke and needs appropriate assessment.
Who Is at Risk of Developing Atrial Fibrillation?
Although AFib can affect adults of different ages, certain factors make it more likely to develop.
People who may have a higher risk include those who:
- Are older, particularly over the age of 65.
- Have high blood pressure or a history of heart disease.
- Have diabetes, obesity, or obstructive sleep apnoea.
- Have an overactive thyroid.
- Have previously experienced AFib or have a family history of the condition.
- Consume excessive amounts of alcohol or smoke.
- Have heart valve disease or have undergone heart surgery.
Having these risk factors does not confirm that you have AFib. If you notice an irregular heartbeat or unexplained cardiovascular symptoms, a medical evaluation is the appropriate next step.
How Is Atrial Fibrillation Diagnosed?
Atrial fibrillation cannot be reliably diagnosed from symptoms alone. A clinician needs to assess your medical history and heart rhythm, usually with an electrocardiogram (ECG or EKG).
The diagnostic process may involve several steps.
1. Medical history and physical examination
Your doctor may ask about palpitations, dizziness, breathlessness, fatigue, previous heart problems, family history, and medications. Your pulse and blood pressure may also be checked.
An irregular pulse can raise suspicion of AFib, but it does not confirm the diagnosis.
2. Electrocardiogram (ECG or EKG)
An ECG records the electrical activity of your heart. It is the main test used to confirm AFib when the abnormal rhythm is occurring during the recording.
The test is non-invasive and generally painless.
3. Holter monitor or ambulatory ECG monitoring
AFib episodes may start and stop before a person reaches a clinic. If a standard ECG is normal but symptoms suggest intermittent AFib, a doctor may recommend prolonged monitoring.
A Holter monitor or another ambulatory ECG device records the heart’s rhythm over a longer period. The duration depends on how frequently the symptoms occur and which monitoring method is appropriate. NICE+1
4. Echocardiogram
An echocardiogram uses ultrasound to create images of the heart. It can help doctors assess the heart’s structure, valves, and pumping function and identify conditions that may be associated with AFib.
5. Blood tests
Blood tests may be recommended to look for underlying or contributing problems, including thyroid disorders, electrolyte abnormalities, and other medical conditions.
6. Additional investigations
Depending on your symptoms and medical history, your doctor may recommend other tests, such as exercise testing, chest imaging, or specialised cardiac investigations.
Not every patient needs every test. Your clinician will choose investigations based on the suspected cause, the results of the initial assessment, and your overall health. NICE+1
What Are the Treatment Options for Atrial Fibrillation?
AFib treatment aims to control the heart rate or rhythm, reduce stroke risk, improve symptoms, and prevent complications.
The most appropriate treatment depends on the type of AFib, symptom severity, stroke risk, other medical conditions, and individual treatment goals. Some people need medication alone, while others may benefit from a procedure. American Heart Association+1
1. Medications to control heart rate
Rate-control medicines help slow the heart rate so that the lower chambers can fill and pump blood more effectively.
Depending on the patient’s condition, a clinician may prescribe:
- Beta-blockers: Such as metoprolol, which can slow the heart rate.
- Certain calcium channel blockers: Such as diltiazem, which may be suitable for some patients.
- Digoxin: Which may be used in selected circumstances.
The choice depends on factors such as heart function, blood pressure, other medicines, and associated conditions. These medicines control the heart rate but do not necessarily restore a normal rhythm.
2. Medications to control heart rhythm
Rhythm-control treatment aims to restore a normal heart rhythm and help maintain it.
Doctors may prescribe antiarrhythmic medicines for selected patients. The appropriate drug depends on factors including heart structure, coronary disease, kidney function, other medications, and the risk of side effects.
Rhythm-control medication requires appropriate medical supervision because some medicines can cause or worsen abnormal heart rhythms.
3. Blood thinners to reduce stroke risk
One of the most important aspects of AFib management is assessing the risk of stroke.
Blood thinners, medically known as anticoagulants, help prevent blood clots from forming. Depending on the patient’s circumstances, treatment may include medicines such as apixaban, rivaroxaban, dabigatran, edoxaban, or warfarin.
Not every patient with AFib needs the same anticoagulation plan. A clinician assesses individual stroke risk, bleeding risk, kidney function, other medical conditions, and relevant treatment guidelines before making a recommendation.
Important: Blood thinners do not directly correct the irregular heartbeat. They help reduce the risk of clot-related complications. Do not start, stop, or change an anticoagulant without medical advice. Aspirin should not be substituted for prescribed anticoagulation for AFib-related stroke prevention without a clinician’s direction.
4. Electrical cardioversion
Electrical cardioversion is a procedure in which a controlled electrical shock is delivered to the heart to restore a normal rhythm.
It is performed in a monitored medical setting, usually with sedation. Doctors consider factors such as how long AFib has been present and the patient’s clot risk when deciding whether cardioversion is appropriate and how to manage anticoagulation before and after the procedure.
Cardioversion can restore a normal rhythm, but AFib may recur.
5. Catheter ablation
Catheter ablation is a minimally invasive procedure used to treat the abnormal electrical signals responsible for AFib.
A specialist passes thin, flexible tubes called catheters through blood vessels into the heart. Targeted energy creates small areas of scar tissue that interrupt the abnormal electrical pathways. Depending on the technique, this may involve heat, cold, or another energy source.
Ablation may be considered when symptoms persist despite medication, when medicines are not tolerated, or as an early rhythm-control option for suitable patients.
It can reduce AFib episodes and improve quality of life, but it is not guaranteed to eliminate AFib permanently. The procedure also has risks, which the treating specialist should discuss with the patient.
6. Left atrial appendage closure
For selected patients who need stroke prevention but cannot take long-term anticoagulants or have other specific clinical considerations, a doctor may discuss left atrial appendage closure.
This procedure closes off the left atrial appendage, a small pouch where blood clots can form in some people with AFib. It is not appropriate for everyone and does not automatically mean that anticoagulants can be stopped immediately or are never needed again.
7. Pacemaker or other specialised procedures
A pacemaker does not directly cure AFib. However, it may be used when a patient also has an abnormally slow heart rate or certain conduction problems, sometimes allowing other aspects of rhythm management to be addressed safely.
Selected patients may require additional specialised procedures based on their heart condition and treatment response.
The key point is that there is no single treatment that is best for every patient. A cardiologist can help determine which approach offers the most appropriate balance of symptom relief, stroke prevention, and treatment risks. American Heart Association+1
What Happens If Atrial Fibrillation Is Left Untreated?
Untreated or inadequately managed AFib can increase the risk of serious complications. The level of risk varies between individuals, but the main concerns include the following.
Stroke
When the atria do not contract normally, blood may pool in parts of the heart and form a clot. If the clot travels to the brain and blocks a blood vessel, it can cause a stroke.
AFib-related strokes can be disabling or life-threatening. Appropriate assessment of stroke risk and anticoagulation, when indicated, are therefore essential.
Heart failure
A persistently fast or poorly controlled heart rate can weaken the heart muscle over time. AFib can also worsen existing heart failure, creating a cycle in which each condition makes the other more difficult to manage.
Reduced quality of life
Frequent palpitations, fatigue, breathlessness, and dizziness may interfere with work, exercise, sleep, and routine activities.
Other cardiovascular complications
AFib may coexist with other heart conditions and contribute to a greater overall cardiovascular burden. Proper management of blood pressure, diabetes, and other associated conditions is important.
Not every person with AFib will develop these complications. Early diagnosis, appropriate treatment, and regular follow-up can help reduce the risk. American Heart Association+1
How Can You Reduce the Risk of AFib Episodes and Complications?
Lifestyle changes cannot replace necessary medical treatment, but they can help improve overall heart health and support AFib management.
1. Manage high blood pressure
Check your blood pressure as advised by your clinician and follow your prescribed treatment plan. Poorly controlled hypertension is an important risk factor for AFib and other cardiovascular conditions.
2. Maintain a healthy weight
If you are overweight, gradual and sustainable weight management may help reduce AFib burden and improve associated conditions. Your doctor can help you set realistic goals.
3. Exercise regularly
Regular physical activity supports cardiovascular health. Walking and other moderate activities may be suitable for many people, but the right exercise plan depends on your symptoms and medical condition.
Avoid suddenly starting intense exercise if your AFib is uncontrolled or you have concerning symptoms. Ask your clinician what level of activity is safe for you.
4. Limit alcohol
Alcohol can trigger AFib in some people. Avoiding alcohol or reducing consumption may be particularly helpful if episodes appear to follow drinking.
5. Prioritise good sleep
Maintain a consistent sleep schedule and discuss loud snoring, interrupted breathing, or excessive daytime sleepiness with your doctor. These may be signs of sleep apnoea, which is associated with AFib.
6. Manage diabetes and cholesterol
Keeping blood glucose and cholesterol under appropriate control can help reduce overall cardiovascular risk.
7. Review caffeine, stimulants, and medications
Caffeine tolerance varies. Pay attention to your individual triggers and discuss repeated symptoms with your clinician. Also disclose over-the-counter medicines, supplements, and stimulant-containing products because some may affect heart rate or rhythm.
8. Stop smoking
Stopping smoking supports cardiovascular health and helps reduce other heart-related risks.
9. Attend follow-up appointments
Regular follow-up helps your healthcare team review symptoms, check medication effectiveness, reassess stroke risk, and adjust your treatment when needed. American Heart Association+1
Can Atrial Fibrillation Be Cured?
There is no universal answer because AFib behaves differently in different people.
Some people have occasional episodes that stop spontaneously. Others have persistent AFib that requires medication or a procedure to restore a normal rhythm. Catheter ablation can substantially reduce episodes in selected patients, but recurrence remains possible.
Even if treatment restores a normal rhythm or symptoms disappear, the risk of stroke must still be assessed. A person should not stop prescribed anticoagulants simply because they feel better or a heart monitor shows a normal rhythm.
The realistic goal is to find an effective, individualised treatment plan that manages symptoms, addresses contributing conditions, reduces complications, and supports a good quality of life.
When Should You See a Cardiologist for AFib?
Consider arranging a medical assessment if you experience:
- Repeated episodes of a racing, fluttering, or irregular heartbeat.
- Unexplained dizziness or lightheadedness.
- Breathlessness during routine activities.
- Persistent fatigue or reduced exercise tolerance.
- A newly detected irregular pulse.
- Symptoms alongside a history of high blood pressure, heart disease, diabetes, or thyroid problems.
If AFib has already been diagnosed, seek medical advice if episodes become more frequent, symptoms worsen, or your prescribed treatment causes concerning side effects.
Seek emergency care immediately for chest pain or pressure, severe breathing difficulty, fainting, or possible stroke symptoms. Do not wait for a routine appointment.
Which Doctor Treats Atrial Fibrillation?
A cardiologist is the specialist who evaluates and treats heart rhythm disorders such as AFib. Depending on your needs, you may also be referred to a cardiac electrophysiologist, a cardiologist with specialised training in the heart’s electrical system.
A doctor can evaluate your symptoms, arrange an ECG and other appropriate tests, assess stroke risk, and explain whether medication, monitoring, or a procedure is suitable.
If you are experiencing symptoms of an irregular heartbeat, arranging an appropriate medical assessment is an important step towards understanding the cause and protecting your heart health.
Frequently Asked Questions
1. What is the main symptom of atrial fibrillation?
The most recognised symptom is an irregular, rapid, fluttering, or pounding heartbeat. Other symptoms include fatigue, dizziness, weakness, and shortness of breath. Some people have no noticeable symptoms.
2. Is atrial fibrillation dangerous?
AFib can be serious because it increases the risk of blood clots, stroke, and heart failure. However, many people manage the condition successfully with appropriate treatment, monitoring, and lifestyle changes.
3. Can atrial fibrillation go away on its own?
Some episodes, particularly paroxysmal AFib, stop on their own. However, an episode ending does not mean the underlying condition or stroke risk has disappeared. Medical assessment is still important.
4. Can stress cause atrial fibrillation?
Emotional stress may trigger symptoms or episodes in some susceptible individuals, but stress alone does not explain every case of AFib. Other causes and associated conditions should be assessed.
5. Can atrial fibrillation cause a stroke?
Yes. AFib can allow blood to pool in the heart, increasing the possibility of clot formation. If a clot reaches the brain and blocks an artery, it can cause an ischaemic stroke. Appropriate stroke-risk assessment and treatment can help reduce this risk.
6. Is an ECG enough to diagnose AFib?
An ECG can confirm AFib when the irregular rhythm is present during the recording. If episodes come and go, a single ECG may not capture them. A doctor may recommend a Holter monitor or other prolonged rhythm monitoring.
7. What is the difference between AFib and a normal irregular heartbeat?
AFib is a specific abnormal rhythm caused by disorganised electrical activity in the atria. Other conditions, including premature beats, can also cause an irregular pulse. An ECG is needed to identify the rhythm accurately.
8. Can people with AFib exercise?
Many people with AFib can remain physically active, but the appropriate level of exercise depends on heart rate control, symptoms, and other medical conditions. Ask your healthcare professional for individual advice, especially if you experience dizziness, chest discomfort, or breathlessness during activity.
9. Do all patients with AFib need blood thinners?
No. The decision depends on an individual’s risk of stroke and bleeding, other health conditions, and current clinical recommendations. A clinician should make this assessment rather than prescribing or stopping anticoagulants based on symptoms alone.
10. Which test is best for detecting atrial fibrillation?
An ECG is the standard test for confirming AFib. When episodes are intermittent, ambulatory ECG monitoring may be needed to detect the abnormal rhythm.
11. Can atrial fibrillation be treated without surgery?
Yes. Many people are managed with medications, monitoring, and lifestyle changes. Electrical cardioversion and catheter ablation are additional options for selected patients; catheter ablation is generally performed through blood vessels rather than open-heart surgery.
12. When should I seek emergency treatment for an irregular heartbeat?
Seek emergency care for an irregular heartbeat accompanied by chest pain, severe breathing difficulty, fainting, or symptoms of a stroke, including sudden facial drooping, weakness, or difficulty speaking. Do not delay care even if symptoms improve.
Conclusion
Atrial fibrillation is a common heart rhythm disorder that can cause palpitations, fatigue, dizziness, and shortness of breath, although some people have no symptoms. Its most important potential complications include stroke and heart failure.
The good news is that AFib can often be managed with an individualised combination of medication, appropriate procedures, risk-factor management, and regular follow-up. Recognising symptoms, obtaining an accurate diagnosis, and understanding your treatment options can help you make informed decisions about your heart health.
If you suspect you may have AFib or have been diagnosed with it, consult a qualified healthcare professional to discuss appropriate testing and treatment. Do not ignore possible emergency symptoms or change prescribed heart medication without medical guidance.
