Recognising the Symptoms of Atrial Fibrillation (AFib)
Introduction: Understanding AFib Symptoms
Atrial fibrillation (AF or AFib) is the most common heart rhythm condition in Australia. It affects how the heart beats, leading to a fast or irregular rhythm that can impact your energy, comfort, and long-term health. Recognising the symptoms of atrial fibrillation is crucial—early diagnosis and treatment can reduce your risk of complications like stroke and heart failure.
Not everyone with atrial fibrillation experiences symptoms. But for those who do, knowing what to look out for could be the first step toward protecting your heart.
Watch: What AFib Means for Your Health
This short video explains the impact of atrial fibrillation on your health and why recognising symptoms early is so important. It’s a great first step in understanding the condition and what you can do about it.
Common Symptoms of Atrial Fibrillation
The symptoms of atrial fibrillation can vary in severity and frequency. You may experience only one or two of these or notice changes that come and go.
Typical symptoms include:
- Heart palpitations – A fluttering, pounding, or racing heartbeat
- Fast or irregular pulse – Heart rates can often range between 100–200 beats per minute during atrial fibrillation episodes
- Shortness of breath – Especially during physical activity or when lying down
- Fatigue or tiredness – Feeling drained even with minimal activity
- Chest discomfort – Pressure, tightness, or pain
- Dizziness or light-headedness – Feeling faint or unsteady
- Increased need to urinate – Particularly during atrial fibrillation episodes due to the additional flow of blood through the kidneys
Symptoms can occur suddenly or gradually. Some people have very strong symptoms, and in others, the symptoms may feel subtle or vague.
What Does Atrial Fibrillation Feel Like
Here’s some of the ways that our patients have described the symptoms of atrial fibrillation in their own words:
- “It feels like a fish flopping in my chest.”
- “Thunder rumbling from inside.”
- “Like a butterfly fluttering wildly.”
- “My heart pounds like I’ve run a marathon—when I’ve done nothing.”
These personal descriptions reflect just how varied and unsettling the experience of atrial fibrillation can be.
Silent or Asymptomatic AFib: A Hidden Risk
Some people with atrial fibrillation have no noticeable symptoms at all—this is known as silent or asymptomatic atrial fibrillation. Despite the lack of symptoms, the risk of stroke and heart complications remains just as high.
In fact, atrial fibrillation is sometimes only discovered during routine checks, while being prepared for an unrelated surgery, or when a complication like a stroke occurs. That’s why regular heart health screening is so important, especially for older adults and people with risk factors such as high blood pressure or sleep apnoea.
When to Seek Medical Advice
If your heart symptoms have not yet been diagnosed, then working out what the symptom is caused by is important. See your GP or cardiologist if you:
- Feel a sudden or ongoing irregular heartbeat
- Experience shortness of breath, dizziness, or chest discomfort
- Notice increased fatigue or find you can’t tolerate usual activities
Call an ambulance or attend the closest emergency department if you have the following symptoms – these may be signs of a stroke.
- Sudden Weakness or Numbness: This can affect the face, arm, or leg, usually on one side of the body. 
- Trouble Speaking or Understanding: Difficulty speaking clearly, slurred speech, or difficulty understanding what others are saying. 
- Vision Changes: Sudden blurring, double vision, or loss of vision in one or both eyes. 
- Loss of Balance or Coordination: Dizziness, unexplained falls, or trouble walking. 
- Severe Headache: A sudden, severe headache with no known cause. 
- Difficulty Swallowing: This can be a symptom of some types of stroke. 
Even occasional episodes should be checked— this is common in paroxysmal atrial fibrillation, but can progress over time if left untreated.
Sometimes it can be hard to get a diagnosis from your symptoms and medical examination at the doctor, especially if your symptoms are not present at the time that you attend your GP or cardiologist appointment. We have further information here for people with intermittent symptoms who may be able to use a smart watch or device to try and capture your heart rhythm information when episodes occur.
Diagnosing Atrial FibrillationÂ
If you’re experiencing symptoms or are at risk of atrial fibrillation, your may have your initial investigations at your GP. In addition, QCG offers a range of cardiac diagnostic services including the following that may be requested by your GP or cardiologist.
- Electrocardiogram (ECG): Measures your heart’s electrical activity
- Holter monitor: A portable device that records your heart rhythm over 24–48 hours
- Event monitor:
- Echocardiogram: Uses ultrasound to assess heart function and structure
Our cardiologists use these results to develop a tailored management plan for you.
What Happens if Atrial Fibrillation is Left Untreated?
If untreated, atrial fibrillation can lead to:
- Stroke: Due to blood clots forming in the heart
- Heart failure: When the heart can’t pump blood effectively
- Progressive worsening of symptoms: Episodes may become more frequent and harder to treat
Frequently Asked Questions About AFib Symptoms
Yes—AFib can be paroxysmal (come and go), persistent (ongoing) or even permanent. You can read more about these in our What is Atrial Fibrillation page.
There are some initial Women may be more likely to report fatigue, anxiety, and palpitations. Men may report chest discomfort more frequently.
AFib causes a rapid, chaotic rhythm in the atria. Other arrhythmias (like atrial flutter or SVT) may have more regular patterns or different symptom profiles.
If you’re experiencing any of these symptoms, don’t wait. Early evaluation can make all the difference in protecting your health.
📞 Contact QCG to book an appointment (you’ll need a referral from your GP)
📄 Learn more about cardiac diagnostic testing
📚 Read more about Atrial Fibrillation
