More Info: Acid reflux CAN cause coughing. Acid reflux is a common cause of chronic cough. In fact, acid reflux is one of the top three causes of chronic cough.
The Difference between Acid Reflux and GERD
Acid reflux is medically referred to as gastroesophageal reflux (GER). GER is common and occurs when the lower esophageal sphincter, the muscle at the bottom of the esophagus, does not close properly allowing stomach contents and digestive juices to rise up into the esophagus causing discomfort and pain. The terms acid reflux, acid regurgitation, and gastroesophageal reflux are generally used interchangeably. 
Gastroesophageal reflux disease, or GERD, is a more severe form of acid reflux. Persistent acid reflux occurring more than twice a week is considered GERD. 
What Is a Cough?
The airways are lined with cough receptors designed to clear the airways of lung irritants. When stimulated by irritants such as smoke, dust, or foreign bodies, the cough reflex is triggered in attempts to expel the irritant from the body. 
The body reacts to anything that irritates the cells along the air passages by coughing.
Why Acid Reflux May Cause Coughing
In the case of acid reflux, the cough reflex can be triggered by aspiration of the contents of the stomach into the esophagus, which then stimulates the cough reflex. Acids in the lower portion of the esophagus may also stimulate a cough reflex through neural reflex arcs without any aspiration into the esophagus. 
Acid Reflux a Common Cause of Chronic Cough
GER is one of the top three causes of chronic cough along with postnasal drip syndrome and asthma. (Postnasal drip is the leading cause in 41% of the cases, followed by asthma in 24% of the cases, and GER in 21% of the cases.) Though it is a leading cause of chronic cough, GER is usually not initially suspected because of the absence of common symptoms such as heartburn and acid regurgitation. Interestingly, forty-three percent of the time, cough is the only symptom of GER.