“General Hospital” actor John J. York taking hiatus from show due to blood and bone marrow disorder diagnoses

General Hospital star John J. York is speaking out about his ongoing health battle.

The veteran actor, who has starred as Mac Scorpio on the soap opera since 1991, revealed that he is currently undergoing treatment for two separate blood and bone marrow disorders in a social media post on Wednesday.

"I said I was going to give you an update on the reason I'm taking a little hiatus from General Hospital and here it is," York said. "So last December of '22, I was diagnosed with myelodysplastic syndromes, or MDS, and multiple smoldering myeloma — two blood and bone marrow disorders."

Myelodysplastic syndromes are "a group of cancers in which immature blood cells in the bone marrow do not mature or become healthy blood cells," according to the National Cancer Institute. Smoldering myeloma is "a precancerous condition that alters certain proteins in blood and/or increases plasma cells in bone marrow," but it "does not cause symptoms of disease," per the NCI.

Craig 'Crash' Hattori/Imagespace/Shutterstock John J. York

"Over the past many months, I've had three bone marrow biopsies, many chemo treatments — I have another one coming up in a couple of weeks — and I'm closing in on a blood stem cell transplant," York said. "I've been working with some wonderful people at Be the Match to find a potential donor on their registry."

He also encouraged GH fans to consider donating and — for those between the ages of 18 and 40 — joining Be the Match's registry not just for him, but for "thousands and thousands of other people who are in need of a donor." York has launched his own fundraising page on the organization's website too.

"I just want to say thanks for all the support over the years," York said. "This isn't goodbye, this is just 'so long.' I'll have to take a break [from General Hospital] for at least three, maybe four months, but I'll be back."

"Thanks a lot. Check out Be the Match. Do whatever you can," he continued. "Thanks for your patience, thanks for your time, thanks for your prayers. I'll keep you updated. Talk to you soon."

News of York's diagnoses comes less than a week after he announced on social media that he was temporarily stepping away from his role on General Hospital.

"Hey kiddos, just want to let you know that I will be taking a brief hiatus from the show in a few weeks," he wrote. "I'm in the process of getting some important information. So hang tight, and I'll be in touch."

Sign up for Entertainment Weekly's free daily newsletter to get breaking TV news, exclusive first looks, recaps, reviews, interviews with your favorite stars, and more

Related content:

• General Hospital star Genie Francis will no longer defend Luke and Laura's rape scene: 'I think that the story was inappropriate'

• Luke and Laura forever! General Hospital just killed off iconic character Luke Spencer

• See Carly and Jason's wedding photo from General Hospital