This open access book provides basic concepts on Integrated Diagnostics and Theranostics with special emphasis on different human thyroid diseases.   Thyroid diseases  are increasingly detected (incidentally in many cases) but are clinically negligible in a significant proportion of patients. Accordingly, it is urgent to move from the simple disease detection to a reliable disease characterization in order to concentrate efforts on patients in need of tailored disease management.   The current scenario of in vitro and in vivo diagnostics, is fastly moving toward the Integrated Diagnostics (i.e. convergence of imaging, pathology and laboratory tests with advanced information technology). Furthermore, the integration of different information will aid clinicians to properly select treatments and stratify patients  prognosis over time.