How do you handle requests for early departure or working from home due to health reasons?

I am curious about the criteria you set when an employee requests to leave early or work from home for health reasons!

If you visit a hospital before or during work, I think you can handle it by obtaining proof such as a medical certificate.

This is a case where the employee states that they want to leave early or work from home because they are not feeling well...

Even if I get a medical certificate, it’s difficult to determine if leaving work early or working from home is actually absolutely necessary.

However, if we leave it entirely to the department head's discretion every time, I think the standards will vary from team to team...!

What criteria do other companies use to process requests for early departure or working from home due to health reasons?

I am also curious if you have a separate procedure in place for department head approval or work availability verification, in addition to documentation such as medical certificates!