• Mayo Clinic Minute: Why antacids – not your inhaler – may be the key to treating your asthma

Asthma is a relatively common lung problem, usually caused by allergies, heavy exercise or chemical exposure in the workplace. But Dr. Alexei Gonzalez Estrada, a Mayo Clinic allergy and immunology specialist, says most people don't realize heartburn could be making their asthma worse.

Watch: The Mayo Clinic Minute

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Think of your lungs and airway as an upside-down tree.

"And what happens is you have inflammation of your airway tree, Dr. Gonzalez Estrada says. "And what happens is it gets full of gunk, and that's when people get wheezing, shortness of breath, chest tightness."

That's asthma.

"Heartburn can also irritate the airway, and you're never going to catch your asthma if you don't treat your heartburn symptoms, as well," Dr. Gonzalez Estrada says.

Heartburn is one of the first things he asks patients about when they come in for asthma treatment. He says there are two theories about why heartburn worsens asthma symptoms.

"There's ... the theory that [acid] actually goes all the way up into your throat, and it goes into your airway and irritates your airways," he says. "Or the other theory that [acid] actually irritates your nerves, which are connected to the same nerves that are in charge of you having coughing."

So the next time your asthma acts up, ask your health care provider if heartburn could be the real problem.