The 30-year-old performer was hospitalized in July for the condition.
ET's Rachel Smith spoke with the 30-year-old "Cut" singer on Monday at the Bowery Ballroom in New York City ahead of her concert. Kelly is currently on her Take Control Tour in North America in support of her new EP, Tori, which is out now.
She reflected on her recent hospitalization for blood clots, saying, "That just made me even more grateful and not want to take a single moment for granted. Looking out in the audience and seeing all my amazing fans again has been keeping my spirits high."
Noting that she believes "in everything happening for a reason," Kelly opened up about her July medical scare that left her hospitalized for a week.
"It happened out of nowhere. I was feeling just a little tired throughout the day, and my heart rate was kind of high," she recalled to ET. "I was at dinner with my husband [André Murillo] and so thankful he was there because I ended up collapsing and was rushed to the hospital and they found blood clots."
Kelly said she had "no idea" the blood clots were there and that there was no history of clots in her family. To this day, the performer still doesn't know the cause of the clots.
"On one end, it was scary, and then on another end, I did feel this sense of unexplainable peace that it was gonna be OK," she said. "I just felt like God had me and it was gonna be OK, but yeah, definitely in the midst of that it was just kind of a confusing whirlwind."
These days, Kelly is treating her condition with medication.
"It seems like blood clots are manageable with medication and blood thinner, so that's how I'm able to tour and kind of get back to my normal self," Kelly shared. "But that's what I've learned so far is that it seems to be manageable with those."
Kelly has been cleared by doctors to return to the stage and said that getting back to performing for the first time in more than four years has helped her recovery.
"I'm able to tour now. I'm back healthy and so it was definitely scary, but I think it's definitely given me a different outlook on life and just being so grateful that I made it through that and am here now," she said.
Kelly's EP is available now and her Take Control Tour will run through the end of the month.