Alcohol is metabolized in a standard way. However, not everyone feels the same effects of alcohol, and the amount of time alcohol stays in the system can vary depending on a person's body type, age, gender, and other factors. That's mostly because alcohol concentrations can vary between people and situations. Blood alcohol concentration, or BAC, refers to the amount of alcohol in your blood relative to the amount of water in your blood. Several factors can affect your BAC and how you react to alcohol, including your age and weight, drinking alcohol on an empty stomach, medications you take, and whether you have chronic liver disease. Also, having several drinks of alcohol in a short period of time, which is known as compulsive drinking, can cause serious health complications. The CDC says that excessive alcohol use, including underage drinking and binge drinking (having 5 or more drinks on one occasion for men or 4 or more drinks on one occasion for women, can increase risks for health problems such as injuries, violence, liver disease, and cancer.