Normally, your heart’s natural pacemaker sends out regular electrical impulses. AF happens when those impulses fire off from different places in the atria (the top chambers of the heart) in a disorganised way.
People with AF have an irregular and sometimes fast pulse. You can check to see if you might have AF simply by feeling your pulse.
What causes AF?
Causes include high blood pressure, heart valve disease, thyrotoxicosis (overactive thyroid gland) and excess alcohol consumption.
It’s also associated with coronary heart disease. But in many patients no underlying cause can be found. Sometimes the AF can be resolved once the underlying condition has been dealt with.
What are the symptoms of AF?
Symptoms can include palpitation (being aware of your heart beat), tiredness, shortness of breath, dizziness or feeling faint. However, some people only have mild symptoms, while other people have no symptoms at all.
Read Mike Butler and Jim Kelly's stories of living with AF.
How can AF be detected?
AF can be detected by feeling the pulse at your wrist. The pulse will feel irregular and beats may be variable in strength.
Some people don’t realise they have AF. It’s only discovered when they have a pulse check or ECG (a test which records the electrical activity of the heart).
Make sure you know your pulse. If your pulse is irregular or if you’re concerned in any way about your pulse you should make an appointment to see your GP.
A quick guide to checking your pulse
- Put one of your hands out so you’re looking at your palm.
- Use the index/first finger and middle finger of your other hand and place the pads of these fingers on the inside of your wrist.
- You should place them at the base of your thumb near where the strap of a watch would sit.
- Press lightly and feel the pulse. If you can’t feel anything press slightly harder or move your fingers around until you feel your pulse.
- Once you’ve found your pulse, continue to feel it for about 20-30 seconds.Feel the rhythm of the pulse and check if it’s regular or irregular.
Listen to examples
Regular pulse rhythm
Irregular pulse rhythm
Is an irregular pulse always due to AF?
Occasional irregularities such as missed beats or extra beats are very common and usually nothing to worry about.
AF on the other hand is continuously irregular with no pattern to it at all.
What are the complications of AF?
It can increase the risk of a blood clot forming inside the chambers of the heart, which can lead to a stroke. AF increases stroke risk by around four to five times.
Although AF can greatly increase the risk of stroke, there are other factors that can contribute to a stroke. These include smoking, high cholesterol, high blood pressure, physical inactivity, being overweight and diabetes.
With appropriate treatment the risk of stroke can be substantially reduced. An anticoagulant (blood thinner) drug called Warfarin is the most effective treatment to reduce the risk of stroke in people with AF.
What should you do if your pulse is irregular?
If your pulse is irregular or if you’re concerned in any way about your pulse you should make an appointment to see your GP.
Find out more
Atrial fibrillation booklet
Designed for people with atrial fibrillation, and for their family and friends. This booklet describes the heart's normal rhythm, what atrial fibrillation is, diagnosis, complications, and different types of treatment.
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This booklet is also available to download in large print
Read more about Atrial fibrillation in Heart Matters Magazine
Promoting better understanding, diagnosis, treatment and quality of life for individuals with cardiac arrhythmias.
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Atrial Fibrillation Association
Providing information, support and access to established, new and innovative treatments for Atrial Fibrillation.
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Help us beat AF
Around 800,000 people in the UK have AF - roughly one in 100 - and most are aged 55 and over.
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