Symptoms of atrial fibrillation include:

• Heart palpitations.
• Irregular pulse.
• Shortness of breath, especially during physical activity or emotional stress.
• Weakness, fatigue.
• Dizziness, confusion.
• Lightheadedness or fainting (syncope).
• Chest pain (angina).

Atrial fibrillation is often discovered during routine medical checkups, because many people do not have symptoms. Others may notice an irregular pulse but do not have other symptoms.

Mild symptoms may develop immediately. More serious problems may develop after the start of atrial fibrillation and over the course of several days. Therefore, it is important to identify and treat atrial fibrillation as soon as possible to avoid serious problems.

Serious complications such as a stroke, heart attack, or heart failure may occur before atrial fibrillation is discovered.