Hepatobiliary diseases encompass a broad spectrum of conditions affecting the liver and bile ducts, which are critical for digestion and metabolism. These diseases can range from minor ailments to severe conditions that require immediate medical intervention. Understanding the fundamental aspects of these diseases, including their symptoms, causes, and diagnostic methods, is crucial for early detection and effective management. This article provides an in-depth overview of hepatobiliary diseases, focusing on common disorders such as hepatitis, cirrhosis, gallstones, and cholangitis. Additionally, it explores the importance of liver function tests and bile production in diagnosing and monitoring these conditions.