Is personal/unpaid LOA a thing?

I’m completely out of sick time and my work schedule makes it literally impossible for me to schedule doctors appointments on days that I work and when I try to schedule appointments on one of my 2 days off, it’s always months and months out. I work 11-7 every single day (most doctors offices close by 4 or 5) so I have put my health issues on the back burner for the last few months and because I waited so long, my symptoms are worsening to the point where I can no longer put it off. With that being said, I have several doctors appointments coming up with several different specialists within the next 2 weeks. I scheduled them for days and times that I’m supposed to be at work (because those are the only appointments ever available) and decided that I’m just gonna have to take an intermittent LOA which is when you still work but just take certain days off for appointments, however, I was told by the man on the phone at target pay and benefits that it will most likely get denied since I don’t have a “serious diagnosis” from a doctor yet which leads me to my next question ..

How are so many people on this sub AND at my store just taking LOA’s whenever they feel like it? I have literally seen so many people saying they took LOA’s simply because they wanted a break and didn’t have any sick time. What is the way around getting an LOA without a medical crisis going on? I refuse to put my health on the back burner any longer and I need to figure out what is actually going on with my health and if that means I need to take a week or two off of work without pay, then so be it. Do I just go to my stores HR and ask for a personal unpaid leave or do I still have to go through pay and benefits?