It is believed that pathology is the fundamental cause of disease. Therefore, the “Principles of Diseases; POD” block is essential since it gives the students a solid understanding of the fundamentals of pathology and microbiology, pharmacology, biochemistry, and molecular biology. The POD block must come before the integrated blocks on "systems," to facilitate students’ understanding. To lay the foundation for a more thorough study of the body's organ systems, the block introduces basic concepts of processes such as infections, inflammations, repair, hemodynamic disorders, including thrombosis, embolism, infarction, shock, and neoplasia, all of which contribute to the majority of morbidity and mortality worldwide.