A “Survivor” fan favorite is facing his most difficult challenge yet.

Ken McNickle, a finalist in season 33 of the hit reality show, shared his cancer diagnosis this week in an Instagram post and, in a follow-up video, revealed the three signs he ignored.

“I deliberated for a while about whether to share or not, but I ultimately decided to because I’m hoping this chapter in my story can help others,” McNickle captioned the original post, which featured a carousel of images of him at a doctor’s appointment, looking contemplative with medical patches attached to his chest.

“I’ve made some mistakes in the process and should have taken care of myself better and sooner,” McNickle admitted, urging others to be proactive about treatment.

“If you have a health concern, don’t sit on it,” he said. “Get yourself checked. There’s no valid reason not to. Not one.”

In a follow-up video, McNickle outlined the three symptoms and warning signs he ignored, introducing the clip with a “trigger warning.”

“If you don’t like gross medical details, get out now,” he cautioned.

“I waited almost a year until my skin was tearing open to get this checked,” he said, pointing towards his heart. “Had I gone in sooner, it would have been a simple procedure — not a three-inch hole in my chest.”

McNikle added that despite seeing blood in his stool every morning, he delayed seeking treatment for nearly three months, at which point it was “confirmed” that his “insides were tearing open.”

While the kind of cancer McNikle is battling remains unclear, blood in the stool is a telltale sign of colorectal cancer.

An ER doc previously called the symptom the “one condition where you should go to the emergency room today.”

McNikle, a former model and father of one, also admitted that he postponed seeking medical attention until a groin growth had reached alarming proportions.

“I waited until that lump on my testes had grown to the size of the other two before getting it checked,” he added.

Again, while McKickle has yet to disclose a specific cancer diagnosis, the aforementioned lump could indicate testicular cancer, which, shockingly, has the highest prevalence in men between 20 and 40.

Reflecting on his choices, McNickle lamented, “I have been so f—king stupid.”

He acknowledged how a childhood steeped in toxic masculinity and the lifelong pressure to perform it contributed to his adult health crisis.

“I heard the words, ‘Stop crying. Don’t be a baby. Don’t be a bitch. Don’t be a p—y. Just be a man,” he said. “And yeah, I am thinking that had something to do with it.”

McNickle recognized that his experience is not an exception, calling out the “epidemic” of men’s health.

“We need to be talking more about why men are 50% less likely to go to a doctor for physical ailments and 60% less likely to get help with mental and emotional issues,” he captioned the video.

Fans were quick to flood the comments section with words of support and appreciation.

“Thank you for sharing all this. It’s so incredibly important to talk about and normalize men struggling and not getting the help they need,” said one.

“You aren’t the only man who put off the doctor for far too long. Hopefully, your story can help others to understand this,” said a second.

“Your honesty and vulnerability are really brave. That’s being a true man. Sending hugs and hope for a healing journey,” added a third.

McNickle’s season of Survivor aired in 2016 and was themed “Millennials vs. Gen X.” he made it all the way to the final three before losing to Adam Klein in an anonymous vote.

McNickle’s designation as a millennial cancer patient is in keeping with a disturbing trend. Research suggests Millennial Americans are at a higher risk of developing 17 cancers compared to older generations.

Indeed, mllennials are twice as likely to get colorectal cancer compared to their Boomer counterparts.

Meanwhile, rates of appendix cancer have quadrupled among millennials, defined as the generation born between 1981 and 1996.