(Concern) How does cystitis occur?

When does cystitis occur?

It occurs due to stress or irregular eating habits.

Someone I know is very sick and has trouble using the bathroom.

So I went to the hospital for tests and treatment.

I was very worried, but everything is fine and there are no issues.

People say they are sick, but the machine is fine.

I felt relieved because they said there was nothing wrong.

Is there a way to prevent it in advance?