Cardiology is specific to heart health, and implies the person is a specialist doctor. She is studying cardiology to become a cardiologist.
Pro Tip 2/3
Technical Context
Used in medical settings, often referring to departments, treatments, or research related to the heart. The cardiology wing at the hospital handles all the heart surgeries.
Pro Tip 3/3
Formal Usage
Cardiology is formal, used in academic and healthcare environments, not in casual conversation. The conference on cardiology was attended by many renowned heart surgeons.