Why do I have atrial fibrillation?

Atrial fibrillation is by far the most common abnormality of the heart rhythm in the Western world. More than 45 million people worldwide are affected by atrial fibrillation.1 Over the coming years, this number is predicted to rise significantly.2-4 In recent years, the number of atrial fibrillation cases has risen to an extent that the term ‘global epidemic’ has been used when talking about the condition.5

A commonly asked question by patients who have been diagnosed with atrial fibrillation is ‘why do I have the condition?’ There are a number of factors that increase the risk of developing atrial fibrillation. On note however, in some patients, atrial fibrillation occurs without any of the known risk factors.

Risk factors for atrial fibrillation:

  1. Age
    • There is a significant increase in the chances of developing atrial fibrillation after the age of 65 years. The risk continues to increase progressively after this age.6
  2. Being overweight
  3. High blood pressure
  4. Diabetes
  5. Smoking
  6. Alcohol excess
  7. Inadequate levels of exercise
    • The relationship between exercise and AF is discussed in more detail here.

It is important to note that the risk factors outlined above are closely interrelated. For example, patients who have a history of excess alcohol intake have a higher likelihood of being obese and have high blood pressure. Furthermore, these risk factors also increase the chances of developing other heart conditions, including having a heart attack.

In addition to the risk factors outlined above, patients who have other heart conditions may also have a higher risk of developing atrial fibrillation. This is especially the case for patients who have heart failure and patients who have had a previous heart attack.

How the above risk factors ultimately cause atrial fibrillation is not fully understood. Current research evidence indicates that these factors change the electrical characteristics of the left top chamber of the heart, where atrial fibrillation originates from. The electrical abnormalities associated with atrial fibrillation is discussed in more detail here.

It is important to note that even if you have a diagnosis of atrial fibrillation and have one or more of the risk factors for atrial fibrillation, it is not too late to change the trajectory of the condition. Potential beneficial lifestyle changes are discussed in Dr Mahida’s article which was published in the Daily Telegraph (included here).


1.         Benjamin EJ, Muntner P, Alonso A, et al. Heart Disease and Stroke Statistics-2019 Update: A Report From the American Heart Association. Circulation. 2019;139(10):e56-e528.

2.         Krijthe BP, Kunst A, Benjamin EJ, et al. Projections on the number of individuals with atrial fibrillation in the European Union, from 2000 to 2060. Eur Heart J. 2013;34(35):2746-2751.

3.         Di Carlo A, Bellino L, Consoli D, et al. Prevalence of atrial fibrillation in the Italian elderly population and projections from 2020 to 2060 for Italy and the European Union: the FAI Project. Europace. 2019;21(10):1468-1475.

4.         Go AS, Hylek EM, Phillips KA, et al. Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) Study. JAMA. 2001;285(18):2370-2375.

5.         Kornej J, Borschel CS, Benjamin EJ, Schnabel RB. Epidemiology of Atrial Fibrillation in the 21st Century: Novel Methods and New Insights. Circ Res. 2020;127(1):4-20.

6.         Heidenreich PA, Trogdon JG, Khavjou OA, et al. Forecasting the future of cardiovascular disease in the United States: a policy statement from the American Heart Association. Circulation. 2011;123(8):933-944.