Non- specific health symptoms can be very frequently encountered among the general population. Within the group of people suffering from symptoms of unclear origin an increasing number attribute their health problems to electromagnetic fields of internal and/or external electromagnetic field sources. Therefore, these people call themselves "hypersensitive to electricity" or "electrosensitive". The percentage of electrosensitive people varies from country to country.
In a common research project the Department of Clinical Engineering of the Institute of Biomedical Engineering together with the Department of Environmental Health at Karolinska Hospital, Stockholm investigated whether three different groups of people could be identified by clinical investigation and biophysical measurements. The respective groups were electrosensitive people with severe symptoms in daily life, people with skin problems attributed to work with video display terminals (VDU) and a healthy control group.