Cyrus, 21, came down with flu-like symptoms two weeks ago and was prescribed medication typically used as an alternative to penicillin, to which she is allergic.
The singer ended up being allergic to that treatment, and a severe reaction left her bed-ridden in a Kansas hospital for days, reported People magazine.
"It was so scary. When you're allergic to something, you're literally poisoning yourself, so I had just been poisoning myself for a week with something I didn't know I was really, scary allergic to," she said.
Cyrus rode in an ambulance for the first time and indulged in ice cream while recuperating.
"I was just laying there, I'm hooked to all these machines, every two hours some woman comes in and pokes me with a needle, and it's just miserable.
"I ended up doing way too much online shopping, and whatever they had me on to make me not in pain, I made very questionable choices about what I bought. I'm like, 'I don't know what this hot pink mini skirt is that I bought in the hospital," she added.