What is the most likely cause of nocturnal cough in a patient with GERD?

The most likely cause of nocturnal cough in a patient with gastroesophageal reflux disease (GERD) is acid reflux into the esophagus. In GERD, the lower esophageal sphincter fails to adequately protect the esophagus from the stomach contents, including acid. When a person lies down, the position can exacerbate the reflux process, allowing more acid to travel up the esophagus.

This acid exposure can irritate the esophagus and also stimulate a coughing reflex, particularly during the night when the patient is recumbent. Notably, the cough may be particularly pronounced during sleep, as the body is not in an upright position where gravity can assist in keeping stomach contents in their proper place. This cough can be persistent and is typically worse at night or in the early morning.

Other options may contribute to respiratory issues or cough but are not as directly tied to the GERD mechanism:

• Esophageal strictures may lead to swallowing difficulties but are less frequently associated with nocturnal cough directly.

• While asthma exacerbation can involve cough and might occur at night, it is not directly related to GERD unless there is a clear overlap with aspiration due to severe reflux.

• Cardiac issues may cause cough but are more atypical and would