Heartburn, or GERD (Gastroesophageal reflux disease) is a burning sensation in the lower part of the esophagus. It is a chronic disorder in which stomach acids flow backwards into the esophagus – causing a burning sensation. An estimated 75% of people with asthma also experience frequent heartburns. Although there are possibilities of heartburn being related to asthma, the exact nature of any relationship is still uncertain.

According to experts, there are a few possible premises of how heartburn and asthma may be related. One of them is - the acid flow backward can damage to the linings of the lungs, throat and airways, and trigger persistent coughs. This can in turn make breathing difficult, and cause asthma attacks.

Another hypothesis is that, inhaling small amounts of stomach acid back into the lungs and the esophagus can trigger a nerve reflex that narrows the airways so that the acids cannot enter. This can cause shortness of breath, hence facilitating the development of asthma.

Apart from these, a study has shown that people with asthma may be twice as likely to develop heartburn disease as those who don’t, even though more evidence are required to prove the validity of the analysis. 

However, if a person has both asthma and heartburn, care should be taken for the proper treatment of both, to avoid severe asthma attacks or worsening of heartburn symptoms.