Welcome to the Centers for Disease Control and Prevention’s (CDC’s) HIV Risk Reduction Tool. This tool will help you learn about the risk of getting HIV or transmitting HIV to someone else and also how to lower that risk. A person’s risk of getting or transmitting HIV has to do with many factors that are discussed in this tool. Some of the factors make your chances of getting or transmitting HIV higher; some of them make your chances lower. The most important thing to know is that by learning about the factors that increase or decrease HIV risk, you can protect yourself and help others avoid getting HIV. You will be more informed and better able to take charge of your health. This tool was developed for adults. It includes sexually explicit language that is necessary for clarity and accuracy, but may not be suitable for individuals under 18 years of age.