It’s estimated that more than 75 percent of people with asthma also have GERD, according to the Cleveland Clinic. And in a study in a February 2017 issue of the American Journal of Respiratory and Critical Care Medicine, researchers examined possible factors that cause frequent asthma flares and found that higher body mass index, gastroesophageal reflux, and chronic sinusitis were each linked with frequent exacerbations of asthma. “Clearly, there’s a connection between reflux and asthma, especially adult-onset asthma,” says Michael Vaezi, MD, a professor of medicine and otolaryngology and director of the Swallowing and Esophageal Disorders Center at Vanderbilt University Medical Center in Nashville. “The lung doctors and gastroenterologists know about this connection, but patients may not.”

The mechanisms behind the association aren’t crystal-clear, but there are a few theories. One is that if someone has GERD, aspiration of stomach acid into the airways can cause irritation there, leading to breathing difficulties or a persistent cough. “If you have acid reflux and you regurgitate high enough, you can get a bronchospasm that can trigger asthma,” Dr. Vaezi notes. Another theory is that acid reflux may trigger a protective nerve reflex that causes the airways to tighten in order to prevent the stomach acid from entering the lungs; this can lead to a bronchospasm too. There isn’t a single test that can definitively identify reflux as the cause of asthma-like symptoms in those with GERD. But “not responding to steroids is a big red flag to consider GERD in a patient with severe asthma,” notes Kaiser Lim, MD, a consultant in pulmonary and critical care medicine at the Mayo Clinic in Rochester, Minnesota. To determine if reflux is exacerbating asthma, doctors typically consider a person’s symptoms and their response to treatment. In terms of treatment, a doctor might prescribe aggressive use of acid-suppressing medication to see if the asthma-like symptoms improve, Vaezi says. (If they don’t, it’s less likely that reflux is the culprit behind the airway symptoms.) Meanwhile, the effects can go the other way too — meaning that asthma can aggravate acid reflux, thanks to pressure changes that occur inside the chest and abdomen during an asthma attack. “Wheezing reduces pressure in the chest, and coughing changes pressure in the LES [lower esophageal sphincter] valve, which can pull gastric contents up and cause reflux,” explains Vaezi. “It becomes that vicious cycle of is it the chicken or the egg” that’s causing symptoms.

How to Control GERD and Asthma

Fortunately, getting good control over one of these conditions can help improve symptoms and minimize flare-ups of the other one, too. “If you have one triggering the other, by treating one, you’re treating the other — you’re breaking the cycle by taking one element away,” Vaezi says. Those who have nocturnal asthma and heartburn are more likely to respond to proton pump inhibitors (PPIs) and their asthma is more likely to get better as a result, he adds. But in a subset of people with severe asthma, GERD treatments could actually worsen their breathing troubles. A study in the September 2017 issue of the Journal of Clinical Immunology found that people with difficult-to-treat asthma who had been treated with acid-suppressing medication had alterations in the bacterial environment in their airways that reduced their responsiveness to corticosteroid medication for their asthma; this unresponsiveness can lead to persistent inflammation in their lungs and more severe asthma. “It’s a delicate balance to try to manage both GERD and asthma-like symptoms, and proper identification or diagnosis of these conditions is essential. We have patients with difficult-to-control asthma due to untreated or inadequately treated GERD,” Dr. Lim says. If you have reflux and airway symptoms such as wheezing, coughing, or shortness of breath, it’s in your best interest to work closely with a gastroenterologist and an asthma specialist to get the upper hand on both conditions.