If there is no one in your immediate circle who has been diagnosed with atrial fibrillation, you'd be forgiven for not knowing what it was. One of the lesser-discussed heart conditions, atrial fibrillation causes the heart to beat irregularly and abnormally fast. And while awareness of atrial fibrillation is low, it is in fact quite common. There are even some quite famous faces who have been diagnosed with the condition.
Intrigued? Check out this gallery to learn all about atrial fibrillation.