EW examines what's behind singers' vocal-cord crisis—and how these artists get their pipes back in shape.

Credit: Michael Tran/FilmMagic

Back in February at the Grammys in L.A., Sam Smith joined Mary J. Blige on stage for a rousing performance of his smash hit “Stay With Me.” It was a triumphant moment for the artist, who picked up multiple awards for In the Lonely Hour, one of the biggest albums of 2014. But three months later, his luck ran out: He suffered bleeding on his vocal cords and had to cancel a run of tour dates. After undergoing a procedure and resting up for just under two months, he returned to the road for his U.S. trek. “My throat is looking bloody fantastic,” he wrote on Instagram July 16. “So it’s amazing news.”

Smith isn’t the only artist to recently suffer in silence. Meghan Trainor postponed shows in July due to a vocal hemorrhage, while back in 2011 Adele, the singer with the golden voice, was plagued with a polyp, which can develop if bleeding is left untreated. Artists ranging from Steven Tyler to Julie Andrews to John Mayer have also had to mute their pipes to heal. “I’ve been on tour for the better part of this year, which has been amazing but can be a lot of work for my little vocal cords,” Trainor tells EW. “They’re like muscles, and I feel like I basically pulled a muscle.”

If it seems that visible cases of vocal-cord issues among music’s MVPs are on the rise, they are. So what’s behind the recent spate? “Most of the performers that I care for, they know how to sing,” says Dr. Steven M. Zeitels, a leading surgeon at Massachusetts General Hospital who has treated Smith and Adele. “More often than not, the injuries occur because of their unbelievable work ethic. I don’t think there’s an increase in injuries. I think it’s being diagnosed more frequently because of awareness.”

One major factor in vocal troubles, according to Zeitels, is the rigors of touring, which is all the more important to an artist’s commercial success given the decline in album sales. “It’s amazing how many shows can be done in a row—that makes things more complicated today,” says Zeitels, who notes that injuries often start if artists perform while under the weather. Zeitels also says issues are more likely in females: “Men speak from about 100 to 140 hertz, the number of times per second their cords collide, while women speak between 180 and 240 hertz. So there are more collisions and more potential for vocal lesions.”

A big misconception about the cause of hemorrhaging: Artists don’t use their diaphragms properly. “Singing teachers worked with imagery like ‘Sing from your diaphragm,’ which doesn’t make sense at all,” Joan Lader, a coach who worked with Madonna on 1996’s Evita, says. “The diaphragm is a muscle—you can’t sing from it.”

While artists like Smith might get sidelined, treatment has become easier due to technological advancements. Zeitels, for one, inserts a minimally invasive laryngoscope into a patient’s mouth. It pulses a laser, originally designed to treat lesions on babies’ skin, to shrink blood vessels, while not scarring vocal cords. “What’s good for a baby’s skin is good for a vocal fold,” Zeitels says.

After the procedure, he advises singers to rest their voices (no talking!) for three weeks. And once they’ve healed, they should take it easy. “If they get ill, they need to be able to cancel shows,” he says. Lader agrees: “We advise not to do more than a couple shows in a row and a day off in between,” she says. “This is a stressful business. They need to balance their lives.”

A version of this story appeared in Entertainment Weekly issue #1374, on newsstands Friday, July 24.