Millions of people worldwide are affected by the prevalent clinical issue, gastroesophageal reflux disease (GERD). Both conventional and unusual symptoms can identify patients. Many people with GERD benefit from symptomatic relief and are shielded from consequences by acid suppression medication. Our capacity to recognise and manage disease consequences has improved thanks to developments in diagnostic and therapeutic technologies. One of the biggest typical gastrointestinal problems treated by physicians and primary care doctors is GERD, which is characterised by heartburn and regurgitation symptoms. GERD prevalence has increased, especially in North America and East Asia. Proton pump inhibitors (PPIs) have been the cornerstone of medical treatment for GERD for the past thirty years. However, clinicians and patients are becoming more aware of the adverse effects of the PPI class of medications recently. Additionally, surgical fundoplication has significantly decreased, while the evolution of non-medical therapeutic methodologies for GERD has increased. In the treatment of GERD, lifestyle changes are crucial. Individual variances can be seen in how GERD symptoms change in response to different diets. The study implies that there may be a connection between reflux occurrence and salty foods, chocolates, fat-rich foods, and aerated beverages, even if there is insufficient data to support this theory. In lifestyle modifications, other factors involved are the head of the bed, patients' lying down position, smoking, fat or obesity, and physical exercise. The number of reviews focusing on various diagnostic techniques and treatment modalities is very less, so this review puts emphasis on these areas. This review also covers GERD and its symptoms, epidemiology, and pathophysiology, but significantly focuses on diagnosis, treatment, and lifestyle modification effects.