Teens develop respiratory problems within 30 days of using e-cigarettes, new study finds. Experts say this is a wake-up call.

For years, e-cigarettes were seen as a slightly healthier way to smoke or as a tool to help chronic smokers quit. But a growing body of research has found that e-cigarettes, like "regular" cigarettes, can also be damaging to your health.

The use of e-cigarettes is growing, especially in kids. They're the most commonly used tobacco product among youths, according to the Centers for Disease Control and Prevention (CDC). In 2022, 2.55 million American middle and high school students reported having used e-cigarettes in the past 30 days, per CDC data, including 3.3% of middle school students and 14.1% of high school students.

A new study from the Ohio State University has found that teens with an e-cigarette habit quickly develop noticeable respiratory symptoms. But why might that be the case and what happens next? Here's what you need to know.

What the study says

The study found that teens who start to use e-cigarettes can show symptoms of bronchitis and shortness of breath in as little as 30 days.

What are the key findings?

The study, which is published in the journal Thorax, analyzed data from several waves of surveys. In 2014, the researchers asked 2,097 teens of a mean age of 17.3 from the Southern California Children’s Health Study about their e-cigarette, regular tobacco and cannabis use, along with any health symptoms they experienced. Three additional waves of surveys were taken in 2015, 2017 and 2018. By wave 4, more than 15% of those surveyed said they used e-cigarettes.

During the first wave, 23% of the teens surveyed said that they had asthma. Symptoms of bronchitis were common in each wave, ranging from 19.5% of study participants to 26%, depending on the survey.

The researchers found that use of e-cigarettes within the past 30 days was linked to an increased risk of wheezing, symptoms of bronchitis and shortness of breath. The odds of wheezing were 81% higher in those who had used e-cigarettes over the past 30 days compared to those who had never smoked. The chances of having symptoms of bronchitis was twice as likely, and shortness of breath was 78% more likely, than in those who had never smoked.

What experts think

Doctors say the study results are significant. "These findings highlight the important message that use of e-cigarettes [is] associated with health harms," Dr. Michael Ong, professor in residence of medicine and health policy and management at UCLA Health, tells Yahoo Life. "These products are not harmless."

Dr. Robert Hamilton, a pediatrician at Providence Saint John’s Health Center in Santa Monica, Calif., and host of the podcast The Hamilton Review: Where Kids and Culture Collide, agrees. "The overall perception out there is that e-cigarettes are better than cigarettes, but nothing is for free," he tells Yahoo Life. "It isn't like you get a pass when you use e-cigarettes."

Why might e-cigarettes cause symptoms in such a short period? That is probably due to lung irritation, Hamilton says. "The lungs are fragile entities," he says. "They're highly sensitive to environmental smoke. Your body's response is to immediately reject it, and you cough." Wheezing can also be a reaction people experience when their lungs are irritated, he says.

When people routinely use e-cigarettes, it leads to routine irritation in the airways, Hamilton explains. Unfortunately, people — including kids — tend to use them a lot, Ong says. "E-cigarette use is often high intensity, particularly among youth, which can accelerate the health harms, such as respiratory symptoms," he says.

Why it matters

Hamilton says this is just more evidence that e-cigarettes are not good for people. "The lungs are saying, 'Don't do this,'" he says. "The best advice I can give for kids is, 'Don't go there.'"

Ong notes that while traditional combustible cigarettes involve additional harms, "e-cigarettes also have health risks" — and it's important for people to be aware of them. "We continue to need strong tobacco product regulation to ensure that health harms as identified by this study are accounted for in the regulatory and approvals process for e-cigarettes," he says.