It might be easiest for you to just ask your doctor what s/he would write, and if s/he would be willing to fill out the FMLA without a diagnosis -- which s/he should, as docs are the ones who are most familiar with HIPAA as well.
My company made my doctor go into pretty thorough detail.........but they did know that I had it and was treating.
It's always good to go into these situations with a positive attitude, especially since the terms of the leave under FMLA are supposed to worked out and discussed beforehand. If they get too nosey, just a brief mention of HIPPA should make them realize they have no business asking those questions. One you get an attorney, it puts your employer in a defensive posture which is usually a no win situation for anybody in the long run. I'd lawyer up only as a last resort.
Thank you for your clear, concise answer; I am also doing some investigating on my own before determining if I should seek legal representation before needing FMLA.
There are a few types of employers that are permitted to require disclosure of HCV such as law enforcement and hospitals, doctor's offices, etc. because of the potential of blood exposure. If you aren't involved in any of those fields, then you employer has no rights to know this information.
Your employer also has no rights to know the specific reason for your request for FMLA. Your doctor can simply write a letter stating that you have a serious health condition that makes the employee unable to perform the essential functions of his or her job. Although your employer might feel they deserve to know the specifics, anyone familiar with FMLA should know better than to push this, since you will easily win this challenge. Both HIPPA and FMLA are there for the protection of the employee and should be taken very seriously. Employers less the 50 employees may not be required to offer FMLA, but are still bound by HIPPA rules.