When to worry about dizziness with atrial fibrillation

Atrial fibrillation creates an irregular heartbeat that can reduce how steadily blood moves around the body. You may notice fluttering or pounding in the chest, tiredness, reduced stamina, lightheadedness, or breathlessness. Dizziness can also result from a fast rate, low blood pressure, medicines, or another condition, so a new or changing pattern should be assessed rather than self-diagnosed.

Stop what you are doing and sit or lie somewhere safe. Note when the episode began, how long it lasted, whether your heartbeat felt fast or irregular, and any accompanying symptoms. Take rhythm or blood-thinning medicines exactly as prescribed; do not double a missed dose unless your clinician has told you how. Contact your care team promptly if episodes are more frequent, last longer, or interfere with normal activity.

Call emergency services for chest pain, severe or worsening breathlessness, fainting, new confusion, or sudden facial drooping, arm weakness, speech trouble, or vision loss. Do not drive yourself during these symptoms. Obtain urgent medical advice for persistent dizziness, a sustained racing heartbeat, or repeated near-fainting, especially if treatment has recently changed or you may be dehydrated.

Ask how to record episodes, whether your heart rate and rhythm need checking, and what to do after a missed dose. Discuss how blood-thinning treatment lowers clot risk, which bleeding symptoms matter, and which symptoms mean you should call for emergency help.