Clinically, many friends will ask: “doctor how long this disease treatment program, need a few courses.” But in the end, “course” of what is the connotation of this problem, I guess many people can not say, in fact, the meaning of the course and “distance” meaning similar, we go to travel or business trips, often ask the driver: “to so-and-so place to be How many days will it take to get to so-and-so?” The so-called distance is the time needed to reach the destination, of course, this time is an approximation, just for reference. Therefore, the meaning of “course of treatment” is also the time needed to achieve the therapeutic purpose, of course, this time is also a reference. However, it is an important guide to clinical practice, especially for chronic diseases. If the course of treatment has just begun, has not yet seen the effect, it means that the course of treatment is not enough; if to reach or more than the course of treatment is not effective, it means that the treatment program is not ideal need to be improved.