Breast thermography is a physiological test that provides information on temperature and infrared heat patterns of the breast. Because the skin naturally emits thermal radiation (heat), it is well suited to infrared imaging. Thermography differs from mammography in that it provides information on the biological activity of the breast vs. the gross internal anatomy. Infrared imaging is a functional test, whereas mammography is a structural test.

As a functional test, thermography can detect breast abnormalities that other screening methods cannot identify, namely thermal and vascular changes. The increased metabolic activity seen on a breast thermogram can be an indication of injury, mastitis, fibrocystic breast disease or cancer. These functional changes are thought to take place before the onset of structural changes that can occur in diseased or cancerous states. A persistent abnormal thermogram can alert the physician to the need for further investigation and identify women who need to be more closely monitored.

Because thermograms in a healthy woman remain remarkably constant, serial thermograms can assess tissue changes over time. A healthy initial thermogram serves as a baseline to compare future thermograms against.