Gastroesophageal reflux disease (GERD), also known as acid reflux disease, happens when acid from the stomach flows in the wrong way, to the esophagus. Although asthma and GERD are related to different organs (lungs and esophagus respectively), recent studies have found a strong connection between these two conditions. In fact, according to the American Academy of Allergy, Asthma & Immunology, GERD affects almost 70 per cent of the people with asthma.

The most common symptom of GERD is heartburn. Other symptoms include chest pain, trouble in swallowing and persistent cough. A bitter or sour taste in the mouth and throat is also common.

GERD usually flares up at night. The situation is worse if one is lying down. Acid from the stomach causes the vagus nerve to send signals to the bronchial tubes in the lungs. This gives rise to “bronchoconstriction”. In addition, the acid may reach the throat and then enter down into the trachea, bronchi and lungs. This causes irritation of the insides of the airways, and the cells lining the airways begin to produce more mucus. All these lead to worsening of night-time asthma symptoms, such as coughing, wheezing and difficulty in breathing. This is dangerous since most deaths related to asthma happen at night. Nocturnal also leads to lack of sleep and weakness.