Bernie Sanders had been in Congress for four years when, toward the end of his 1994 reelection bid, he caught a cold.

He stayed on the trail, and a few days later the cold went away. But the hoarseness in his throat didn’t. For months, he had trouble speaking. His voice sounded gravely — “unnatural and strained.” There were times when it rasped so much he had trouble finishing a sentence. He drank water constantly. He looked for a “natural cure”: homeopathic remedies, cough drops, “all kinds of weird teas.” There were articles about it in the local papers, some on the front page. His wife, Jane, and his advisers told him it was becoming a problem. Reporters started asking if he had throat cancer. Really, as he recalls in his 1997 book, Outsider in the House, there was a “benign nodule” on his vocal cords. The doctors recommended surgery — an idea that Sanders, then 54, hated fiercely. He’d never had health problems in his life, let alone surgery, which would require at least three days away from delivering speeches on the campaign trail.

“Being sick,” Sanders writes flatly in his memoir, “is not part of my life.”

The Vermont independent has a deep distaste for much about modern politics: He hates when campaigns are treated as sport and refuses to engage in “political gossip.” For years, he prided himself on never hiring a “slick Washington insider consultant.” But Sanders is also highly attentive to the realities of modern politics. He knows the way something plays. And in 1996, during his next reelection campaign, this time against a well-funded Republican opponent, he knew the story about his voice was playing badly. With great reluctance, after seeing two separate specialists, Sanders agreed to have the surgery.

“If people think that I am in poor health, I’m not going to win this election,” he writes.

More than 20 years later, in the middle of his second presidential campaign, Sanders is bedridden in a Nevada hospital after doctors performed a procedure to open a blocked artery. He’s had to step off the campaign trail, halting his typically relentless schedule of town halls and rallies. And in Iowa, he’s postponed a $1.3 million television ad, his first of the race.

At age 78, just as they did at age 54, two things he hates are converging: real physical limitations, and a focus on his health and personal life that will distract from his “political revolution.”

On Tuesday night, Sanders first noticed some chest pain during a campaign event in Las Vegas. According to a brief statement released the next morning by Sanders’ longtime top adviser, Jeff Weaver, doctors found a blocked artery and successfully inserted two stents. “Sen. Sanders is conversing and in good spirits,” Weaver said. “He will be resting up over the next few days.”

He remains in Las Vegas, where his wife flew to meet him on Wednesday, an official said.