Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page: https://medlineplus.gov/radon.html

Radon

Summary

You can't see radon. And you can't smell it or taste it. But it may be a problem in your home. Radon comes from the natural breakdown of uranium in soil, rock, and water. Radon is the second leading cause of lung cancer in the United States.

There are low levels of radon outdoors. Indoors, there can be high levels. Radon can enter homes and buildings through cracks in floors, walls, or foundations. Radon can also be in your water, especially well water. Testing is the only way to know if your home has elevated radon levels. It is inexpensive and easy. You can buy a test kit at most hardware stores or hire someone to do a test. Radon reduction systems can bring the amount of radon down to a safe level. The cost depends on the size and design of your home.

Learn More

Find an Expert

Children

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.