GERD develops due to multiple contributing factors, most commonly abnormal functioning or weakness of the lower esophageal sphincter. Conditions like hiatus hernia, delayed stomach emptying, stress, pregnancy, connective tissue disorders, obesity, and certain medical illnesses can aggravate reflux. Faulty diet, eating habits, and lifestyle factors such as smoking, alcohol use, lack of sleep, and inactivity also play an important role. Additionally, several medications may trigger or worsen reflux, eventually leading to GERD in susceptible individuals.