Validation message if field is disabled

I have a checkbox on my form (responsive form, SharePoint 2013) that has some rules on it so that it becomes disabled if certain criteria is met. I'd like to display some type of validation message whenever the checkbox is disabled but am not sure how to. Ideally, it would be like how you can type in a validation message if you have a rule to invalidate a field. right now I have a label control with the message I want to display and am trying to find a rule to make this work using "hide". Is there a runtime function to check to see if a field is disabled?