Last Updated on October 19, 2025 by Analgesia team
What is The Main Cause of Atrial Fibrillation
AFib is the medical abbreviation for atrial fibrillation, a type of arrhythmia, or abnormal heartbeat. It occurs when the heart’s upper chambers beat irregularly and very quickly, often more than 400 times per minute.
- Blood clots that can travel to the brain and cause a stroke
- Heart failure
Symptoms of atrial fibrillation include:
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Feeling faint, dizzy, or lightheaded
When your heart beats irregularly, it can’t pump blood efficiently. This drop in blood flow may leave you feeling unsteady, dizzy, or like you might pass out — especially when standing up quickly.• Racing heart (palpitations)
Many people describe atrial fibrillation as a fluttering, pounding, or racing feeling in the chest. These palpitations can come and go suddenly or last for hours at a time.• Tiredness or weakness
An irregular heartbeat forces your heart to work harder to circulate blood. Over time, this strain can drain your energy and leave you feeling unusually tired, even after light activity.• Chest discomfort
Some people experience chest pain, tightness, or pressure when their heart is beating out of rhythm. This symptom should never be ignored, as it can resemble signs of a heart attack.• Difficulty exercising
Atrial fibrillation can make it hard to sustain physical activity. Shortness of breath, fatigue, or a racing pulse during mild exercise are common and often limit endurance.
Causes of AFib
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Atrial fibrillation (AFib) often develops when the heart’s electrical system or muscle tissue becomes damaged. This damage disrupts normal rhythm, causing the upper chambers of the heart (the atria) to quiver instead of contracting properly.
Several conditions and lifestyle factors can trigger or worsen AFib:• High blood pressure (hypertension)
Long-term high blood pressure forces the heart to work harder, thickening and straining its muscle walls. Over time, this pressure can alter the heart’s electrical pathways and set off irregular rhythms.• Heart disease
Conditions such as coronary artery disease, heart valve disease, and heart failure weaken or scar heart tissue. These changes make it harder for electrical signals to travel smoothly, leading to erratic beats.• Congenital heart defects
Some people are born with structural heart problems that interfere with the way electrical impulses move through the heart, increasing the risk of atrial fibrillation from an early age.• Infections
Severe infections — like pneumonia or viral illnesses — can inflame the heart or strain it through fever and dehydration. This temporary stress may trigger AFib in vulnerable individuals.• Sleep apnea
Obstructive sleep apnea causes repeated pauses in breathing during sleep. These episodes lower oxygen levels and spike blood pressure, putting extra stress on the heart and raising the risk of AFib.
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Other risk factors for AFib include:
- Diabetes
- Hyperthyroidism
- Being overweight or obese
- Having had heart, lung, or oesophagus surgery
- Family history
- Lung disease
- Sick sinus syndrome
Some common triggers for AFib include:
• Thyroid disorders
An overactive thyroid (hyperthyroidism) can accelerate the heart rate and overstimulate electrical activity. In some cases, even mild thyroid imbalances can set off AFib episodes.
• Excessive alcohol use
Drinking heavily — especially binge drinking — can irritate heart tissue and lead to what’s often called “holiday heart syndrome,” a temporary bout of AFib triggered by alcohol.
• Stimulants and certain medications
Caffeine, nicotine, and some cold or asthma medicines can overstimulate the heart. Illegal drugs like cocaine or amphetamines are also potent AFib triggers.
• Stress and fatigue
Emotional or physical stress floods the body with adrenaline and cortisol, hormones that can destabilise your heart rhythm when combined with other risk factors.
• Aging
As the heart ages, its electrical system naturally becomes more prone to irregularities. This is why AFib is far more common in adults over 60.
Some lifestyle choices that may help prevent atrial fibrillation include:
- Controlling high blood pressure, high cholesterol, and diabetes
- Not smoking or using tobacco
- Eating a low-salt, low-saturated fat diet
- Exercising at least 30 minutes a day
- Getting enough sleep
- Maintaining a healthy weight
- Reducing and managing stress
AFib can be occasional or persistent. It’s often asymptomatic and undiagnosed.