Electromagnetic fields (EMFs) are invisible areas of energy created by the movement of electricity or wireless communication signals. They exist naturally — the Earth itself generates EMFs — but modern technology has added new man-made sources into daily life.

Natural EMFs come from sunlight, the Earth’s magnetic field, and even lightning. Man-made EMFs are produced by electrical devices like cell phones, Wi-Fi routers, and power lines. Although most man-made EMFs are at low levels, the growing number of sources has led many people to ask how this added exposure might affect health.

Understanding what EMFs are helps you make practical, informed decisions about how to live more safely with them — without unnecessary fear.