What is the most likely diagnosis for a 37-year-old man experiencing heartburn, dyspepsia, and cough at night?

The symptoms described—a combination of heartburn, dyspepsia (indigestion), and a cough that occurs at night—are highly indicative of gastroesophageal reflux disease (GERD). In GERD, stomach acid flows back into the esophagus, leading to irritation of the esophageal lining. The sensation of heartburn, which is often described as a burning pain in the chest, is a hallmark symptom of this condition. Dyspepsia can occur due to the acid disrupting the normal function of the digestive tract, while nocturnal cough can result from acid reflux causing irritation in the throat or airways, especially when a person lies down to sleep.

This condition commonly presents at night because lying flat can exacerbate symptoms due to the anatomical position allowing easier reflux of gastric contents into the esophagus. A diagnosis of GERD would also need to be supported by symptom duration, frequency, and response to initial lifestyle modifications or acid-reducing medications, but the combination of symptoms mentioned aligns very well with GERD.

Other conditions, such as acute cholecystitis, duodenal ulcer, or irritable bowel syndrome, present with different symptom patterns that don't typically include the classic nighttime cough or the specific combination of heartburn