Rush Limbaugh, for decades the leading figure in conservative talk radio, said during his program on Monday that he has advanced lung cancer and will soon begin treatment.

Limbaugh, 69, gave few details about his condition other than a diagnosis from two doctors.

The radio icon said he sought a doctor’s opinion after experiencing shortness of breath on Jan. 12, his birthday.

“I thought about not telling anybody,” he said on the air from his home studio in West Palm Beach, Fla. “It is what it is. You know me, I’m the mayor of Realville. This has happened, and my intention is to come here every day I can and do this program as normally and competently and expertly as I do each and every day because that is the source of my greatest satisfaction professionally, personally.”

He added: “I’ve had so much support from family and friends during this that it’s been tremendous. I told the staff today that I have a deeply personal relationship with God that I do not proselytize about. But I do, and I have been working that relationship tremendously, which I do regularly anyway, but I’ve been focused on it intensely for the past couple of weeks.”

Limbaugh, a former Top 40 DJ, is often credited with saving AM radio by turning what had been a dying music medium into a platform for political discussion — primarily the conservative kind — starting with the national syndication of his program in 1988. His program is carried by about 600 stations, most in the United States, and abroad on Armed Forces Radio.

With a mix of pointed commentary, mock grandiosity and barbed wit, Limbaugh over the years has bashed such targets as feminists (whom he has regularly labeled “feminazis”), environmentalists, Democratic figures such as Bill and Hillary Clinton and President Barack Obama, and the “drive-by media.”

He championed a series of perspectives that became mainstream Republican thought on immigration, fiscal restraint and climate-science denial.

Over the years, he collected a loyal following of listeners, called “Dittoheads” because they agreed with his various pronouncements. But he also racked up his share of controversies and denunciations. He once accused actor Michael J. Fox of faking his symptoms of Parkinson’s disease when Fox appeared in an ad endorsing a Democratic candidate who supported stem-cell research.

He was widely rebuked in 2012 for describing a Georgetown law student, Sandra Fluke, as a “slut” for advocating for mandatory insurance coverage for contraceptives. Those comments sparked a brief advertiser boycott of his program. Limbaugh later apologized for his comments.

Limbaugh’s career survived his temporary loss of hearing in 2001 from an autoimmune disease and his admission in 2003 that he was addicted to prescription painkillers. He was arrested in 2006 for manipulating doctors’ prescriptions in a quest for more oxycodone pills, but the charges were dropped when he agreed to go into rehab.

He was dropped as a football commentator by ESPN in 2003 after outcry about his comments about Donovan McNabb, an African American who was quarterback for the Philadelphia Eagles. Limbaugh said McNabb got more credit than he deserved because “the media has been very desirous that a black quarterback can do well.”

In recent years, Limbaugh has faced a rising tide of competition from podcasts, satellite radio and more stridently conservative websites and broadcasters. President Trump more frequently praises Mark Levin, another widely syndicated conservative radio host and Fox News personality, than Limbaugh. But Limbaugh has remained among the highest-paid media personalities in the world; Forbes magazine estimated that he made $84.5 million in 2018, second only to shock jock Howard Stern ($90 million).

Limbaugh said that he will be off the air for a few days as he consults with his doctors about his treatment options.

Addressing listeners, he said, “Know that every day I’m not here, I’ll be thinking about you and missing you.”

Correction: An earlier version of this story said Limbaugh had started treatment. He is consulting doctors about options. The story has been updated.