Laboratory medical diagnostics is, alongside imaging techniques, the most important auxiliary discipline in everyday medicine. No medical specialty can do without it. Due to automation and the introduction of new methods and parameters, there has been a rapid increase in laboratory medical data and findings produced daily over the past few decades. This textbook provides a practical approach to interpreting laboratory results, the sensible use, and the varying significance of individual values through case studies. The organization into clinical questions such as cardiac laboratory diagnostics, hepatological laboratory diagnostics, etc., offers a quick overview of relevant parameters and facilitates targeted requests for laboratory parameters in clinical practice. The book provides a practical introduction for medical professionals.