Differential diagnosis is the ultmate objective of learning diagnostics in traditional Chinese medicine. In other words, every thing we learn about diagnositics is to know how to make differential diagnosis so that we can treat symptoms and diseases accordingly. In TCM diagnosis, the doctor needs to collect data from the patient in different ways, notably by questioning the patient, observing the patient, and taking the pulses, etc which may be called diagnosis of individual syndromes. And then the doctor needs to determine what syndrome or syndromes are established from the individual syndromes, which may be called diagnosis of integrated syndromes. This book introduces five objective methods of differential diagnosis: