Overview
Cancer is not a single disease, and many factors can affect a person's risk over time. Prevention focuses on lowering exposure to known risks and improving protective habits. Some cancers are linked to lifestyle, infections, environmental exposures, or inherited traits. Even when cancer cannot be fully prevented, screening may help detect it earlier.
Causes and Risk Factors
Cancer risk can be influenced by tobacco use, alcohol, ultraviolet radiation from the sun or tanning devices, certain infections, air pollution, some workplace exposures, excess body weight, low physical activity, and diet patterns. Age is an important factor because cancer becomes more common as people get older. Family history and inherited genetic changes also matter for some cancers. Having a risk factor does not mean a person will definitely develop cancer.
Who Is Affected
Anyone can develop cancer, but risk varies by age, family history, sex, environment, infections, and lifestyle. Some communities have higher exposure to pollution, tobacco marketing, limited screening access, or other barriers to prevention. People with certain inherited conditions or strong family histories may need personalized advice from a healthcare professional. Prevention is relevant across the lifespan.
Prevention
Key prevention steps include not using tobacco, avoiding secondhand smoke, limiting alcohol, protecting skin from too much sun, and avoiding tanning beds. Vaccination against human papillomavirus (HPV) and hepatitis B can help prevent some cancers. Following recommended screening for cancers such as cervical, breast, colorectal, and lung cancer in eligible people can detect changes early. Reducing exposure to workplace and environmental carcinogens is also important.
Diagnosis and Tests
Cancer prevention often includes screening tests rather than tests for symptoms. Screening recommendations vary by age, sex, personal history, family history, and country. Examples include cervical screening, mammography, colorectal screening, and, for some people at high risk, lung cancer screening. A healthcare professional can explain which screenings are appropriate and how often they are recommended.
Diet and Lifestyle
A balanced eating pattern with plenty of fruits, vegetables, whole grains, and legumes can support overall health. Regular physical activity and maintaining a healthy weight may help lower the risk of several cancers. Limiting processed meats and alcohol may also reduce risk for some people. These habits support health but do not guarantee that cancer will be prevented.
When to Seek Medical Care
Speak with a healthcare professional if you have a strong family history of cancer, questions about vaccines or screening, or concerns about workplace or environmental exposures. Medical advice is also important if you notice warning signs such as unexplained weight loss, unusual bleeding, a new lump, a sore that does not heal, or ongoing changes in bowel habits, skin, or swallowing. Early evaluation can help identify whether testing is needed.
Questions to Ask a Healthcare Professional
You may want to ask which cancer screenings are recommended for your age and risk level, whether you should receive HPV or hepatitis B vaccination, and how family history affects your risk. It can also help to ask about quitting tobacco, reducing alcohol use, sun protection, and weight or activity goals. If you work around chemicals or dust, ask how to reduce harmful exposures.