The standard weight for a 172cm boy is usually around 67kg. Standard weight (kg) is about height minus 105 to get the value, but due to the differences in the body and genetic factors, age factors, the weight of each person there will be greater variability, so if in the standard weight of 10% of the fluctuation is a normal situation, but if more than 20% belongs to the wasting or obesity body type. Weight is also related to lifestyle, if the weight is not standard obese or thin, should pay attention to timely life adjustments, through a healthy lifestyle, such as reasonable and balanced nutritional intake, appropriate exercise, adequate sleep, etc., to ensure that the weight is in a relatively normal state. Need to pay attention to if there is excessive obesity or excessive thinning, should be timely to the hospital for examination and diagnosis, as soon as possible after the cause of clear in the guidance of a professional doctor combined with the personal situation for targeted treatment, to avoid delaying the condition caused by adverse effects.