What is the medical term for reflux or "acid reflux"?

The medical term for reflux or "acid reflux" is gastroesophageal reflux disease, commonly abbreviated as GERD. This condition occurs when stomach acid or, occasionally, stomach content flows back into the esophagus, which can lead to symptoms such as heartburn and regurgitation of food or sour liquid.

GERD is characterized by the frequent occurrence of this reflux, which can result in inflammation of the esophagus and other complications if not managed properly. The distinction of GERD as the correct term lies in its specific reference to the gastroesophageal junction where the stomach and esophagus meet, highlighting the role of acid in the reflux.

The other options, such as urinary tract infection, pyelonephritis, and peripheral vascular disease, refer to entirely different medical conditions that do not relate to acid reflux. A urinary tract infection involves the urinary system, while pyelonephritis is an infection of the kidneys. Peripheral vascular disease pertains to circulatory issues in the limbs, none of which involve the esophagus or gastric reflux.