No matter how hard she tried, Bethany Buettner couldn’t stop coughing.

The 12-year-old’s coughs started when she got a mild case of pneumonia last November. But even after the pneumonia subsided, the frantic, hacking coughs wouldn’t go away.

“It started off as just a few coughs, and then it got worse as it went along,” Bethany told The Daily Beast on a Skype call from her home in Severna Park, Maryland. “And then it was unbearable.”

Her father Dennis, who started counting Bethany’s coughs to explain the phenomenon to doctors and her teachers, estimated that she coughed 5,000 times per day—roughly half a million coughs in a three-month period.

Bethany was coughing so much that she couldn’t go to school, and the Buettners eventually pulled her from her seventh grade classrooom. The family tried multiple therapies—pediatricians and pulmonologists, sprays and inhalers. But nothing silenced the barking cough that had taken over their lives.

“ We were wondering, ‘Is she gonna be that little girl who just coughs, with no end in sight?’ ” — Dennis Buettner

“We never let her see it, but [my wife] and I would get together and just be devastated. It showed no sign of stopping […]” Dennis tearfully told The Daily Beast. “We were wondering, ‘Is she gonna be that little girl who just coughs, with no end in sight?’”

The Buettners searched extensively online to try to figure out what was happening to their daughter. One day, they came across a paper written in 1966 by Boston allergist Bernard Berman, who described treating six adolescents with symptoms similar to Bethany’s. That discovery led them to another paper on the symptoms, which Berman called “habit cough,” which referenced a doctor named Ran Anbar.

Dennis emailed Anbar a description of his daughter’s symptoms. Soon after, Anbar pointed the family to a man named Miles Weinberger. Weinberger spent most of his life working as an allergist and pediatric pulmonologist at the University of Iowa, where he wrote extensively on habit cough and a treatment called suggestion therapy.

The therapy is disarmingly simple: the doctor convinces the patient that there’s no need for them to keep coughing, and empowers them to believe that they can overcome it.

After a few emails and phone calls, Weinberger—who has since retired and works as a visiting professor of pediatrics at the University of California San Diego—confirmed that Bethany was likely suffering from habit cough. He offered to attempt to treat her over Skype.

The family was skeptical at first, because so many other treatments had failed.

But within 20 minutes of Skyping with Weinberger, Buettner said, his daughter was cured.

“We witnessed the most miraculous—the most amazing—thing I’ve ever seen in my entire life,” he said, later adding that “[the cough] went from 5,000 to 200, to imperceptible, in just a week or so.”

“ It [felt] like a victory. I did it! Five minutes. ” — Bethany Buettner

A habit cough is not the same as a cough from a regular illness, Weinberger told The Daily Beast. The cough is repetitive, barking, and dry—so much so that nurses at his Iowa clinic used to say they could diagnose it from down the hall. It’s usually triggered by another illness, like a cold or pneumonia, and it doesn’t get worse with exertion.

But the “sine qua non,” he added, “is that it’s totally absent once [the patient] is asleep.”

Why it happens remains a mystery. Anastassios Koumbourlis, chief of pulmonary and sleep medicine at Children’s National Hospital in Washington, D.C., told The Daily Beast that he’s treated hundreds of patients with habit cough—and that, “almost always,” it’s stress-related.

He believes habit coughs start when a patient is stressed and sick with another illness. Their brain links coughing with stress, Koumbourlis said, which causes it to persist long after the real illness has subsided.

The stress and social isolation that comes from having the cough only exacerbates the problem, he added. One mother in Canada, who emailed Weinberger after her 9-year-old daughter had been coughing for nearly two years, told The Daily Beast that the coughing caused serious harm to her daughter’s mental health.

“She felt awful that people were resenting her,” the mother, who asked to remain anonymous, wrote. “Not coughing was painful and pure torture for her. We were starting to get worried about her mental well being. She couldn’t understand what she ‘did’ to deserve this in life.”

Weinberger has a different theory. He argues that an initial illness causes the cough, and that in some patients, it sparks a “vicious cycle” of throat irritation.

Both Weinberger and Koubourlis agree that some form of suggestion therapy is one of the best methods for making that cough disappear.

Weinberger isn’t the first to practice suggestion therapy. Bernard Berman, the allergist who first coined “habit cough” in the paper the Buettners found, noted that he’d treated the cough with “solely... the art of suggestion.” But Weinberger expanded on Berman’s research, developing his own suggestion therapy treatment.

It works like this: He asks patients to find a quiet place, next to a room temperature glass of water. He begins by telling them, with confidence, that their cough is the result of a vicious cycle of irritation and that there’s no reason for it to continue. He then asks them to focus intently on suppressing it for a short period of time—say, a minute—and tells them to keep going for as long as they can, while repeatedly reminding them that they’re learning to control it.

“They’ve got to understand I’m not the one who’s stopping the coughing—I’m just showing them how to do it,” he said.

Once the patient has suppressed a cough for more than five minutes, and appears to believe that they can control the cough on their own, it’s usually over.

“ They’ve got to understand I’m not the one who’s stopping the coughing—I’m just showing them how to do it. ” — Miles Weinberger

Weinberger’s results are impressive. In 1991, Weinberger and his colleagues at the University of Iowa published a report in the Annals of Allergy documenting nine cases of habit cough they saw in their clinic. It took just 15 minutes to stop the cough in eight of the nine cases (one skeptical 14-year-old took 30). Seven of those patients could be reached years later; six said the cough was entirely gone, and one reported only minor self-controlled symptoms.

And in 2016, he and another colleague published a letter to the editor in the Journal of Allergy and Clinical Immunology that documented their previous two decades of treating patients. Out of the 85 patients who underwent suggestion therapy during the clinic visit, 95 percent experienced “complete cough cessation” in the clinic. Families were encouraged to call back if the coughing resumed—but no one ever did.

Some critics have noted that most of the medical literature surrounding habit cough is composed of non-randomized, non-controlled studies. Weinberger agrees that more research would be beneficial—but notes that a clinical trial would be logistically and financially difficult.

Koumbourlis also cautions that not every case will turn out as well as Bethany’s, especially if the patient’s underlying stress is a symptom of more serious mental health issues. Suggestion therapy “may not be the end of the story” in those cases—although he acknowledged that it’s a crucial first step.

Koumbourlis does think Weinberg has one major advantage over other physicians practicing suggestion therapy: He’s retired, which means he can ensure a quiet, focused consultation at any time of day. In the chaos of a clinic, Koumbourlis said, it’s not always so easy.

Because he’s retired, Weinberger generally tries to refer the families that email him to practicing physicians he knows who are comfortable with the procedure. But in some cases, when he doesn’t know anyone in the area, he’ll perform it for free over Skype.

That’s what happened with the Buettners. Bethany said she was skeptical when she was first told about the treatment, because every other medical intervention had failed.

But after five consecutive minutes without a cough, documented in video her father took of the treatment on a site they’ve created for other parents, her hopes improved.

“It [felt] like a victory,” she said, laughing. “I did it! Five minutes.”

And when the session was over, 20 minutes later, Bethany said, she felt even better. “I was speechless,” she said. “I conquered the cough.”

Over the next few days, Bethany repeatedly watched the video of her session with Dr. Weinberger to reinforce the treatment.

“I felt like I was watching my hero,” she said.

The next day, she coughed a few hundred times—and two days later, the cough was almost completely gone. On March 10, she went back to school. Six days later, after she’d gone 48 hours without coughing for the first time, the Buettners declared that their “horror cough” ordeal was over for good.

Buettner has since edited the video of the treatment so that other families can use it. Since posting it on the website, he’s heard from at least two other families—one in California and one in Israel—who believe their children might have habit cough, too.

The Buettners are careful to tell families that they’re not medical professionals, and that they should always seek a doctor’s opinion. But Bethany did have a message for kids in despair: “If I can do it, you can do it too.”

And throughout our 53-minute interview, she didn’t cough once.