That is always a tricky question.

If you tell them that you were let go for attendance due to being sick, all they will hear is "I am unreliable due to health issues."

If you tell them anything else and they find out otherwise during a reference check, they will think you were being disingenuous.

You have some options:

1. Keep it vague, let them know that you were simply looking to move on to a new job with growth opportunities. If they ask for references, reach out to a former co-worker (not your boss or HR) and ask them to be your professional reference. They will validate that you worked for the company and answer to your work ethic.

2. If you go the more honest route, let them know that you had to leave to focus on a personal health issue. You don't need to get into what it was. If they seem apprehensive, you can add that the issue is resolved and won't affect your attendance or ability to do the job.

I don't know if you have a legitimate health issue or not that contributes to your ability to come to work regularly. If that is the case, perhaps you need to work on that, get whatever is causing you to have to miss work looked at and under control or you will constantly find yourself in this position. Attendance issues are one of the top reasons people are disciplined at work/terminated.

Best of luck on your interview today!!! Let us know how it went.