Unhealthy alcohol drinking is negatively influencing health of people and costing a large number of annual finance via "secondhand" effects. Additionally, unhealthy alcohol use covers a spectrum that is associated with varying degrees of risk to health. The investigators hypothesized that unhealthy alcohol drinking resulted in significant increase in anesthetic requirement during general anesthesia. This investigation would clarify the association between unhealthy alcohol use and the intraoperative consumption of anesthetics, and provide clinical evidence for preoperative assessment with respect to the alcohol drinking habit.

Inclusion Criteria:

• ASA physical status I-II
• Chinese
• 19-45yr
• Undergoing general anesthesia

Exclusion Criteria:

• A history of the use of centrally-acting drugs of any sort, chronic pain and psychiatric diseases records.
• Participants younger than 18yr，older than 45yr or pregnancy was eliminated.
• Those who were not willing to or could not finish the whole study at any time.