Gastroscopy is a medical procedure that allows doctors to examine the inside of the esophagus, stomach, and the first part of the small intestine. During the procedure, a thin, flexible tube called an endoscope is inserted through the mouth and down the throat. This tube has a light and camera, enabling the doctor to see any abnormalities, such as inflammation or ulcers, and take biopsies if necessary. The procedure is usually done under mild sedation, so patients feel relaxed and comfortable. Gastroscopy can help diagnose various conditions, including gastroesophageal reflux disease (GERD) and gastritis, and guide treatment options for digestive issues.