Do I have a right to a leave of absence from work for alcohol rehab?

In spite of a recent loss of control with my drinking, I have been doing very well at my new job. It has been recommended that I complete a 28-day in-patient rehabilitation program, and I am trying to decide what to do about my job. I'm not expecting a paid leave; just that my job still be available when I return.

What HIPAA rights might I have? Should I be honest with HR about why I'm leaving?

: http://alcoholdrugstreatment.info/do-i-have-a-right-to-a-leave-of-absence-from-work-for-alcohol-rehab