What causes atrial fibrillation?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 13, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Atrial fibrillation is primarily caused by a combination of structural heart abnormalities and electrical disturbances, with common causes including high blood pressure, coronary artery disease, heart valve problems, heart failure, and previous heart attacks, as well as age, thyroid disorders, excessive alcohol consumption, sleep apnea, obesity, diabetes, chronic lung diseases, and certain medications, as supported by the most recent study 1.

Causes of Atrial Fibrillation

The causes of atrial fibrillation can be divided into several categories, including:

  • Structural heart abnormalities, such as high blood pressure, coronary artery disease, heart valve problems, and heart failure
  • Electrical disturbances, such as abnormal electrical signals that override the heart's natural pacemaker
  • Age, with atrial fibrillation becoming more common after age 65 due to natural heart changes
  • Thyroid disorders, particularly hyperthyroidism
  • Excessive alcohol consumption, especially binge drinking
  • Sleep apnea
  • Obesity
  • Diabetes
  • Chronic lung diseases
  • Certain medications, as noted in the study on drug-induced atrial fibrillation 1

Risk Factors

Several risk factors contribute to the development of atrial fibrillation, including:

  • High blood pressure
  • Coronary artery disease
  • Heart valve problems
  • Heart failure
  • Previous heart attacks
  • Age
  • Thyroid disorders
  • Excessive alcohol consumption
  • Sleep apnea
  • Obesity
  • Diabetes
  • Chronic lung diseases
  • Certain medications As stated in the study 1, multiple clinical risk factors, electrocardiographic and echocardiographic features, and biochemical markers are associated with an increased risk of atrial fibrillation.

Mechanism

The fundamental mechanism of atrial fibrillation involves abnormal electrical signals that override the heart's natural pacemaker, causing the atria to quiver rather than contract effectively, which can lead to blood clots, stroke, and heart failure if left untreated, as explained in the expert consensus document 1.

Personalized Prevention and Treatment

A personalized approach to prevention and treatment of atrial fibrillation is necessary, taking into account the individual's specific risk factors and health modifiers, such as atrial fibrosis and ageing, altered calcium homeostasis, ion-channel dysfunction, and genetic susceptibility, as proposed in the expert consensus document 1.

From the Research

Causes of Atrial Fibrillation

The causes of atrial fibrillation (AF) are complex and multifaceted. Several studies have investigated the relationship between AF and other cardiovascular diseases, as well as the underlying risk factors and mechanisms. Some of the key findings include:

  • Coronary heart disease (CHD) and AF are closely linked, with a strong correlation between the two diseases 2, 3.
  • CHD can promote the progression of AF by affecting reentry formation, focal ectopic activity, and neural remodeling 2.
  • AF can also affect CHD by promoting atherosclerosis, mismatch of blood supply and oxygen consumption, and thrombosis 2, 3.
  • Hypertension is a major risk factor for AF, with high blood pressure increasing the risk of AF and accounting for more cases of AF than other risk factors 4, 5, 6.
  • The relationship between AF and coronary artery disease (CAD) is complex, with the two diseases sharing common risk factors and pathophysiology 3.
  • Inflammation and endothelial dysfunction are central to both AF and CAD, and may be a therapeutic target in the management of these diseases 3.
  • High blood pressure is associated with the strongest evidence for causation of cardiovascular disease, including AF, and has a high prevalence of exposure 6.

Risk Factors

Some of the key risk factors for AF include:

  • Coronary heart disease 2, 3
  • Hypertension 4, 5, 6
  • High blood pressure 6
  • Age 3
  • Coronary artery disease 3

Mechanisms

The mechanisms underlying AF are complex and not fully understood. However, some of the key mechanisms include:

  • Reentry formation, focal ectopic activity, and neural remodeling 2
  • Atherosclerosis, mismatch of blood supply and oxygen consumption, and thrombosis 2, 3
  • Inflammation and endothelial dysfunction 3
  • Left ventricular hypertrophy, atrial fibrillation, heart failure, and coronary artery disease 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Coronary heart disease and atrial fibrillation: a vicious cycle.

American journal of physiology. Heart and circulatory physiology, 2021

Research

Hypertensive heart disease: risk factors, complications and mechanisms.

Frontiers in cardiovascular medicine, 2023

Research

High Blood Pressure and Cardiovascular Disease.

Hypertension (Dallas, Tex. : 1979), 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.