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Atrial fibrillation

Atrial fibrillation (AF) is a common heart rhythm condition that can cause stroke and heart failure. Read about AF symptoms, causes, risk factors and common triggers. You can also learn about treatment and find ways to manage your condition.

In this article

What is atrial fibrillation?

Atrial fibrillation (AF), also called Afib, is a condition which causes an irregular and often rapid heart rate. It can lead to stroke and heart failure.

AF is one of a group of heart rhythm conditions called arrhythmias, which are caused by changes to the heart's electrical impulses.

In a healthy heart, regular electrical signals keep your heart rate at a steady rhythm of between 60 and 100 beats per minute. This is called sinus rhythm. When you have AF, the electrical signals become random and chaotic, causing the top two chambers of your heart (the atria) to twitch or quiver. This causes your heartbeat to become irregular and often faster than usual.

Discover how the heart works.

A healthy heart and a heart affected by atrial fibrillation side by side. One electrical signal triggers a regular heartbeat, while random signals causes an irregular beat.Electrical impulse in a regular heart compared to a heart in AF

How common is atrial fibrillation?

If you're living with atrial fibrillation, you're not alone. AF is the most common type of heart arrhythmia.

A recent study estimated nearly one in 35 New Zealanders between the age of 35 and 74 have been diagnosed with AF - that's more than 60,000 Kiwis. And it's likely there are many more who don't know they have it.

AF is more common as we age, peaking at more than 8% of Kiwis over the age of 85. More Māori are affected than non-Māori, and Māori and Pasifika people are, on average, diagnosed 10 years younger than non-Māori/non-Pasifika.

Types of atrial fibrillation

There are three different kinds of atrial fibrillation:

  • Paroxysmal AF  (also called episodic or intermittent AF) – This is a type of AF that comes and goes. Episodes can last for minutes, hours or days but not usually longer than a week.
  • Persistent AF (also called chronic AF) – AF episodes that last longer than seven days at a time. 
  • Long-standing persistent or permanent AF – AF that has been ongoing for more than a year.

Atrial fibrillation is a progressive disease, so it is not uncommon for people with paroxysmal AF to develop persistent or permanent AF over time. 

What causes atrial fibrillation?

The causes of atrial fibrillation are not always clear. However, there are a number of known risk factors that increase your risk of developing AF. These risk factors include:

AF can sometimes occur in people with no other known conditions. This is called lone atrial fibrillation.

Dr Fraser Hamilton talks about the underlying conditions that can contribute to the development of atrial fibrillation.

Atrial fibrillation triggers

People who have paroxysmal AF may find there are certain things that will trigger an AF episode. Common AF triggers include:


Tiredness and fatigue is a common trigger for AF. Feeling exhausted can worsen your AF symptoms and affect your general health and wellbeing. An important part of AF management includes taking steps to reduce fatigue and improve sleep.


Drinking alcohol can trigger or worsen symptoms because alcohol can affect your heart’s electrical signals. Most people can still enjoy an alcoholic drink if they wish to, but it is important to stay within the recommended guidelines for healthy drinking and avoid binge drinking. For some people with AF it may be best to avoid drinking alcohol, for example:

  • If you are on medication which interacts with alcohol
  • If you have an underlying health condition which is made worse by alcohol.

Talk to your doctor about whether drinking alcohol is safe for you.


The exact link between stress and AF is yet to be determined. Some people with AF believe that stress is a common trigger for episodes of AF. A recent study found that being stressed in the workplace increases your risk AF by 48%.

Being aware of ‘unhelpful’ stressors in your life and taking steps to address these can be beneficial for your AF and for your general health and wellbeing. You can read more on our page about managing stress.


Anxiety can worsen your symptoms of AF. The experience of a fast heart rate during an episode of AF can trigger a cycle of anxiety, increased adrenaline, a further raised heartbeat, and more anxiety. Finding ways of managing anxiety is helpful in AF management and could benefit your general health and wellbeing.


Research has provided mixed messages about caffeine’s role as a trigger for AF, but some people find it can bring on an episode. If you are not used to consuming products that are high in caffeine (coffee, tea, energy drinks) they may affect you more. If you notice a link between caffeine and your AF symptoms, try reducing your caffeine intake.


Nicotine is a cardiac stimulant and can aggravate AF. Smoking is also a known risk factor for heart attack and stroke. Being diagnosed with a health condition such as AF is often a “wake up call” to many. If you are a smoker and would like to quit, there is lots of help available.


For some people AF episodes are more frequent when they have another unrelated illness.


Occasionally medications for other conditions can trigger AF or other arrhythmias. If you think there might be a connection between your AF and a medication, talk to your GP as soon as possible. Do not stop any prescription medication without talking to your doctor first.

Some over-the-counter cold and flu medications can also be a trigger for some people. Talk to your doctor before taking any over the counter medicines, complementary medicines or supplements.


Some people find that being physically active can trigger symptoms of AF. Regular physical activity is hugely beneficial to your health, so don’t let AF stop you from enjoying these benefits. There is a lot that you can do to stay safe while exercising. Find out more on our adjusting to life with atrial fibrillation page.

Dr Fraser Hamilton talks about some of the possible triggers of AF to help you to better control your condition.

Symptoms of atrial fibrillation

The symptoms of AF are different for everyone.

Some people will have no symptoms of AF and will only have the condition diagnosed while being examined by a doctor for something unrelated.

For those who are aware of their AF, some will experience mild symptoms once in a while. Others will experience more debilitating symptoms on a daily basis.

Common symptoms include:

The common symptoms of atrial fibrillation are feeling breathless, light-headed, fatigued, experiencing a racing heart, chest discomfort and having difficulty exercising.

Taking your own pulse

Learn how to take your own pulse.

You can learn how to take your own pulse to see if your heart beat is fast or irregular. There are a number of reasons why your pulse may be slower or faster. This may be due to your age, medications, caffeine, level of fitness or any other illness including heart conditions, stress and anxiety.

You should seek further advice if:

  • your pulse seems to be racing some or most of the time and you are feeling unwell
  • your pulse seems to be slow some or most of the time and you are feeling unwell
  • your pulse feels irregular (“jumping around”), even if you do not feel unwell
  • you have persistent heart rate above 120bpm or below 40bpm.

When to talk to your doctor

If you have symptoms of atrial fibrillation, it is important to talk to your doctor to confirm a diagnosis. Feeling your heart racing (palpitations) is not uncommon and is usually not AF, but it's important to talk to your doctor about it to get the correct diagnosis.

If you've already been diagnosed with AF, it's important to keep track of your symptoms. If they get worse or change over time, you should discuss these changes with your doctor. It may be that your medication needs to be adjusted or that you need another kind of treatment.

Dr Fraser Hamilton talks about how common atrial fibrillation is and what it means for you to have the condition.

If you're experiencing chest pain and other heart attack warning signs call 111 immediately.

Discussing atrial fibrillation with your doctor

Record any symptoms you're experiencing (including any that may seem unrelated to AF), when they occurred and what you were doing at the time.

Write down key personal information, including any family history of heart disease, stroke, high blood pressure or diabetes and any major stresses or recent life changes.

Make a list of all medications, vitamins or supplements that you're taking.

Take a family member or friend along if possible. Sometimes it can be difficult to understand and remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.

Write down questions to ask your doctor. Common questions about atrial fibrillation include:

  • What is likely causing my symptoms or condition?
  • What are other possible causes for my symptoms or condition?
  • What kinds of tests will I need?
  • What's the most appropriate treatment?
  • How much exercise can I do?
  • How often should I be screened for heart disease or other complications of AF?
  • Are there any other treatment options?
  • I have other health conditions. How can I best manage them together?
  • Will I need to see a specialist?


AF can lead to further health problems (complications). The two most serious complications resulting from AF are stroke and heart failure.  

Atrial fibrillation and stroke

People with atrial fibrillation are five times more likely to have a stroke than people without atrial fibrillation. When you have AF, the atria (upper chambers of the heart) don't always squeeze strongly enough to push all the blood into the ventricles (lower chambers). This means blood can pool in the atria and form into lumps (clots). A clot can travel from the heart to the brain causing a stroke.

A step-by-step example showing how a blood clot can form in the heart and travel to the brain.Atrial fibrillation and stroke

Atrial fibrillation and heart failure

Very fast or uncontrolled atrial fibrillation can weaken your heart over time, eventually causing heart failure. This is a condition where the heart is unable to effectively pump around the body.

Both stroke and heart failure are serious conditions. However, by managing your atrial fibrillation and maintaining a healthy lifestyle, you can reduce your risk of complications occurring. This is why it is important to take your prescribed medication even if you don't have AF symptoms.

Diagnosis and treatments

Your doctor will use a range of tests to diagnose your atrial fibrillation. You can read more about these on our diagnosis and treatment page.

Your treatment will depend on your type of atrial fibrillation, its severity and any other health conditions you might have. Learn how atrial fibrillation is treated.


Atrial fibrillation can't always be prevented, however you can reduce your risk by:

  • maintaining a healthy weight
  • managing your blood pressure
  • quitting smoking
  • being physically active
  • eating a heart healthy diet
  • reducing or giving up alcohol
  • avoiding large quantities of caffeine
  • good diabetes management.

You can get more help on ways to achieve this by visiting the lower your risk of heart disease pages of our website.

Staying well with atrial fibrillation

Receiving an atrial fibrillation diagnosis can be overwhelming. But with treatment and lifestyle management, there's no reason why you can't continue with an active, happy life. On our other AF pages we've got lots of information about treatments, medications and tips for your ongoing wellbeing.


Learn how to live with atrial fibrillation