Cancer is a complex group of diseases with many possible causes. In this section you can learn more about the known and possible causes of cancer, as well as general information about carcinogens and how genetics play a role in cancer.
There are a lot of rumors and myths about cancer that make it hard to know what’s true. Here are answers to some of the questions you may have. You'll also learn how potential carcinogens are tested and classified, and find a list of known and probable carcinogens.
Some types of cancer run in certain families, but most cancers are not clearly linked to the genes we inherit from our parents. Learn about the complex links between genes and cancer, as well as genetic testing and how it is used.
Get information on cigarette, cigar, and other types of tobacco use, and learn how it can affect your health, including your risk of cancer.
Get the facts on how diet, physical activity, excess body weight, and alcohol use may affect your risk of cancer.
In the United States and other developed countries, a small portion of cancers are thought to be linked to infections. Learn more about some of the infectious agents linked to cancer in this section.
Learn about the different types of radiation and how exposure to them might affect cancer risk.
Get the facts about some known, possible, and unlikely environmental causes of cancer.
Medical tests and treatments can be an important part of getting and staying healthy. But some types of tests and treatments may actually increase a person's risk of developing cancer. Get the facts about possible links between certain medical procedures and cancer.