Michael Strahan's 19-Year-Old Daughter Isabella Shares Devastating Health Update on 'Good Morning America'

SANTA MONICA, CALIFORNIA - JULY 11: (L-R) Isabella Strahan, host Michael Strahan, and Sophia Strahan attend Nickelodeon Kids' Choice Sports 2019 at Barker Hangar on July 11, 2019 in Santa Monica, California. (Photo by Neilson Barnard/Getty Images)

Good Morning America co-anchor Michael Strahan sat down with his 19-year-old daughter, Isabella, and his co-anchor Robin Roberts, on the Jan. 11 telecast to reveal a devastating health update for the teenager.

The University of Southern California freshman was recently diagnosed with medulloblastoma, a malignant brain tumor primarily found in children—rarely someone of Isabella's age, according to Strahan.

Isabella was diagnosed in late Oct., barely a month after she began to experience symptoms as she commenced her first year of college. "I didn't notice anything was off till probably like Oct. 1," she told Roberts. "That's when I definitely noticed headaches, nausea, couldn't walk straight."

She thought it was vertigo at first, but by Oct. 25, she realized things were much worse when she woke up throwing up blood. She consulted with her family, who insisted she get "a thorough checkup."

Strahan says the doctor who conducted the checkup "saved her life" after insisting on a full workup, including conducting an EKG and sending her for an MRI. "And then she calls me and she's like, 'You need to head to Cedars-Sinai [Medical Center] right now. I'm gonna meet you there,'" Isabella recalled.

They'd discovered a fast-growing tumor larger than a golf ball in the back of her brain. Strahan said he learned of her diagnosis before she did, leading him scrambling to get to Los Angeles—and explaining his lengthy absence from the news show. "...it's still scary because it's still so much to go through. And the hardest thing to get over is to think that she has to go through this herself," he admitted.

He considered bringing her to the East Coast, but doctors told him, "You shouldn't risk trying to put her on a plane...We know what it is and we should get it out as soon as possible."

By Oct. 27, just one day before her 19th birthday, Isabella went under the knife to remove the mass.

The weeks following were a bit of blur, as she was "heavily medicated" and had to learn how to walk again with a little help from her twin sister Sophia. She endured a month of rehabilitation and multiple rounds of radiation, which she just finished yesterday, Jan. 10.

Treatment left her with some nasty side affects, including fatigue, nausea and dizziness, but she's still "feeling good" as she looks forward to having "this whole process to wrap" and focuses on "living every day...through the whole thing."

Next month, she's set to start chemo treatments at Duke Children's Hospital & Health Center in Durham, North Carolina.

"That's my next step. I'm ready for it to start and be one day closer to being over," Isabella said. When all is said and done, she's excited to get back to school and "being back into a routine and something that's enjoyable."

But for now, Isabella is "grateful just to walk or see friends or do something, 'cause when you can't do something, it like, really impacts you." While she's kept the news private til now, she's also looking forward to her new partnership with Duke via a new YouTube series. "I don't wanna hide it anymore 'cause it's hard to always keep in. I hope to just kind of be a voice, and be [someone] who people, maybe [those who] are going through chemotherapy or radiation can look at," she said.

Next: Michael Strahan's Baby Photo Is Melting Hearts As He Celebrates 52nd Birthday