The campaign said Wednesday that doctors have "successfully inserted" two stents, and the candidate is now "conversing and in good spirits," but will be taking a few days to rest.
"We are canceling his events and appearances until further notice, and we will continue to provide appropriate updates," Sanders' campaign said in a statement.
Sanders himself took to Twitter in the afternoon to reassure his followers that he was on the mend and to do some campaigning for his push for universal healthcare.
"Thanks for all the well wishes," Sanders tweeted. "I'm feeling good. I'm fortunate to have good health care and great doctors and nurses helping me to recover."
He added: "None of us know when a medical emergency might affect us. And no one should fear going bankrupt if it occurs. Medicare for All!"
The Vermont senator began to experience some chest discomfort during an event on Tuesday evening in Nevada and was taken to the hospital for a medical evaluation and treatment, where it was discovered that he had a blocked artery.
The Sanders campaign also confirmed to Fox News that they’re postponing a $1.3 million TV ad buy in Iowa that was supposed to hit airwaves in the first caucus state starting on Thursday. The campaign announced the ad just one day ago.
But a senior campaign official told Fox News that overall, “campaign operations are continuing as usual” while the senator is sidelined.
The 78-year-old Sanders, the Democratic field's oldest candidate, sometimes jokingly refers to his age at town halls and other events, especially when interacting with younger participants.
Sanders is one of the leaders in a crowded field vying to be the party's 2020 presidential nominee and take on President Trump in the general election.
His campaign manager, Faiz Shakir, was on a telephone call with supporters Tuesday night but didn’t mention any health concerns about the candidate. Shakir said the “state of the campaign is strong” and he played up Sanders’ strong fundraising total for the third quarter.
Sanders recently canceled some appearances in South Carolina because he lost his voice. The campaign said at the time he felt fine.
Fox News' Paul Steinhauser and Kelly Phares and The Associated Press contributed to this report.