How to setup Nested If statement

[bigukfan]

I am trying to use a nested If statement on the output of a MailMerge field in Word to set bold for particular text.
The problem is the field text can be one of five options:

Never, slight, mild, moderate, severe.

What I want is if the text = "moderate" or = "severe" for it to be bold, otherwise not bold.

I would be grateful for any help. My Field name is AR.