Overdiagnosis means that the doctor’s diagnosis of the patient’s disease is fine and correct, but the patient suffers from a disease that, if the doctor does not diagnose it and the patient does not receive the relevant treatment, the disease will not appear in the patient’s body as a symptom or cause a life-threatening situation. In the history of human medicine, due to the complexity of various diseases, overdiagnosis is not uncommon and unavoidable in clinical practice. Doctors can only rely on their own medical standards and diagnostic instruments to minimize the incidence of overdiagnosis. For example, in a physical examination, a person found a thyroid nodule in the ultrasound of the neck, which was confirmed as papillary thyroid cancer by puncture biopsy and pathology, which was in line with the indications for surgery. The doctor diagnosed papillary thyroid cancer, and eventually the patient underwent surgery to remove it. In this process, the doctor’s diagnosis was in full compliance with the medical requirements and did not have any problems. However, in reality, there do exist a very small number of thyroid cancer patients who do not show any symptoms of thyroid cancer even if they do not undergo surgery or treatment until their death due to other reasons. With the continuous progress of medical science and technology, human beings will surely have more means to cope with over-diagnosis. In life, we still have to believe in medical treatment and science, and once problems are found in the examination, we must actively cooperate with the doctor and do the relevant treatment.