You could have arrhythmia even if your heart is healthy. Or it could happen because of:

• The wrong balance of electrolytes (such as sodium or potassium) in your blood;

• Heart injury or changes such as reduced blood flow or stiff heart tissue;

• Healing process after heart surgery;

• Infection or fever;

• Certain medications;

• Problems with the electrical signals in your heart;

• Strong emotions, stress, or surprise;

• Things in your daily life like alcohol, tobacco, caffeine, or exercise;

• Diabetes;

• Substance use disorder;

• Drinking too much coffee;

• Heart disease, such as congestive heart failure;

• High blood pressure;

• Hyperthyroidism, or an overactive thyroid gland;

• Stress;

• Scarring of the heart, often due to a heart attack;

• Certain dietary and herbal supplements;

• Some medications;

• Structural changes in the heart.

Any interruption to the electrical impulses that stimulate heart contractions may result in arrhythmia.

A person with good heart health will hardly ever experience long-term arrhythmia unless they have an external trigger, such as a substance use disorder or an electric shock.

However, an underlying heart problem can mean that electrical impulses do not travel through the heart correctly. This increases the risk of arrhythmia.