How do I show empathy in interview questions?

Firstly, you need to put yourself in the shoes of the person in the question. How would you feel in their situation? How would you want someone to treat you if that were you? Don't dismiss their problem as if it was only a small issue, show and tell them that you understand where they're coming from. If you can, have an example from your work experience in your head of when you've seen a doctor or nurse be really empathetic with a patient.
For example, if they ask about the importance of empathy, you could talk about how it breaks down barriers between patients and doctors and allows a mutual respect and trust. It also makes it way easier for a patient to express their concerns to someone who they feel really gets them. Also use that example from your work experience to show you've really understood the question and get much-needed extra brownie points.