The effect of alcohol on health is complicated. For individuals with a personal or family history of alcoholism, even mild alcohol use carries risks. For others, moderate alcohol use appears to offer a degree of protection against heart disease. For some people (e.g., those who had a heart attack), moderate alcohol use can further damage the heart muscle. And for all people, excessive alcohol use is extremely dangerous to both the drinker and people around him or her. This article helps to sort out the research that has been done on the effects of alcohol on health. It concludes with a self-test for people who are concerned that they may be alcohol dependent.