Bradycardia is a medical condition characterized by an abnormally slow heart rate, typically defined as fewer than 60 beats per minute in adults. It can occur naturally in well-trained athletes but may also signal underlying health issues, such as Heart disease, electrolyte imbalances, or problems with the electrical conduction system of the heart. Symptoms can include fatigue, dizziness, and fainting. Treatment depends on the underlying cause and severity of the condition.