Idiopathic pulmonary fibrosis (IPF) is a chronic lung condition that causes scarring in the lungs. Symptoms include difficulty breathing and a persistent cough.

IPF is strongly associated with gastroesophageal reflux disease (GERD), a condition where stomach acid flows back into the esophagus.

It’s estimated that up to 90 percent of people with IPF have GERD. Having GERD is generally considered a risk factor for IPF, but research is ongoing to determine the exact relationship between the two conditions.

There are two lines of thought concerning people with both GERD and IPF.

Some researchers think GERD comes first and causes lung fibrosis, or scarring. Others think IPF comes first and puts pressure on the esophagus, causing GERD.

In any case, more research is needed to find the cause of IPF and develop effective treatments.

GERD may be connected to the aspiration of tiny particles of stomach acid into the lungs over time. According to a 2015 study, some experts think this microaspiration plays a role in producing scar tissue in the lungs.

Other experts, as seen in a 2016 case study, suggest that this microaspiration may be responsible for acute episodes of IPF. This case study also notes that many people with both GERD and IPF do not have the usual GERD symptoms. The authors recommend that doctors carefully investigate and treat GERD in people with IPF.

It can be beneficial to treat GERD in people with GERD symptoms, no matter whether IPF or GERD comes first. Individuals who do not have GERD symptoms can decide on a case-by-case basis whether to try GERD treatment.

An older 2011 study looked at many factors affecting the survival rates of people with IPF. One factor was the use of GERD medications, specifically proton pump inhibitors (PPIs) and H2 blockers. People who used GERD medication had median survival rates that were about twice as long as those of people who didn’t use medication.

People who used GERD medication also had less lung scarring. The study authors cautioned that more research is needed and that it’s possible IPF may cause the development of GERD instead of the other way around.

According to a 2021 study, the PPI esomeprazole may help reduce lung scarring. This is partly because esomeprazole regulates the activity of genes that are overactive in IPF.

A small 2013 study of people with IPF found that those taking GERD medication had fewer acute episodes of IPF and a slower decline in their breathing capability. The authors suggested that GERD is a contributing factor in IPF and that antacid therapy may be beneficial.

On the other hand, research such as a 2016 study and a 2019 study concluded that there was no benefit to taking antacids.

If you have GERD along with any symptoms of IPF, ask a doctor to check for IPF. IPF is very rare and difficult to diagnose, but you’ll have a better outcome if it’s caught early.