People whose faces flush red after consuming alcohol likely have a problem breaking down acetaldehyde, alcohol's first metabolite. While this is more common in people from East Asia and women, it can appear in other groups.
The inability to break down acetaldehyde is traced to a genetic alteration that creates a less efficient version of the enzyme that breaks acetaldehyde down. As a result, acetaldehyde accrues in the body. This condition may have both positive and negative impact on health. People with this reaction may have an elevated risk of esophageal cancer as a result of drinking alcohol. However, people with this reaction have lower alcoholism rates, although that may stem from the fact that drinking causes harmful side effects.
Another warning sign from facial flushing is an elevated danger of developing hypertension, or high blood pressure. According to a study of 1,763 Korean men, those who flushed after drinking but still consumed more than four drinks a week had more than twice the danger of high blood pressure in comparison to men who did not drink. Men who did not flush only increased their risk of high blood pressure if they drank nine or more alcoholic beverages in a week.