A blood test is a lab analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via finger-prick. General purpose of this lecture is to present on Blood Pathology. Types of blood tests: Biochemical analysis; Molecular analysis and Cellular analysis. Here also briefly present on process of blood sample collection. Blood Pathology involves following tests: Blood culture, Blood film, Platelet count, Widal Test, Ammonium Ion etc. Any Abnormal Results Mean patient have a blood disorder.