Electromagnetic hypersensitivity (EHS) is a claimed sensitivity to electromagnetic fields, to which negative symptoms are attributed. EHS has no scientific basis and is not a recognised medical diagnosis. Claims are characterized by a "variety of non-specific symptoms, which afflicted individuals attribute to exposure to electromagnetic fields".
Those who are self-described with EHS report adverse reactions to electromagnetic fields at intensities well below the maximum levels permitted by international radiation safety standards. The majority of provocation trials to date have found that such claimants are unable to distinguish between exposure and non-exposure to electromagnetic fields. A systematic review of medical research in 2011 found no convincing scientific evidence for symptoms being caused by electromagnetic fields. Since then, several double-blind experiments have shown that people who report electromagnetic hypersensitivity are unable to detect the presence of electromagnetic fields and are as likely to report ill health following a sham exposure as they are following exposure to genuine electromagnetic fields, suggesting the cause in these cases to be the nocebo effect.
As of 2005 the WHO recommended that claims of EHS be evaluated to determine if a person claiming to be affected by EHS has a medical condition that may be causing the symptoms the person is attributing to EHS, to determine if the person has a psychological condition, and to assess the person's environment for issues like air or noise pollution that may be causing problems. Cognitive behavioral therapy may be helpful in managing the condition.
Some people who feel they are sensitive to electromagnetic fields may seek to reduce their exposure or use alternative medicine. Government agencies have enforced false advertising claims against companies selling devices to shield against EM radiation.
Middle age, female sex and poor perceived health was found to be associated with electomagnetic hypersensitivity (EHS). Of a group of self-reporting EHS sufferers (n=91), more than half had EMF-related symptoms more often than once a week, and the mean number of years experiencing EHS was 10.5. More than half of the EHS group reported that their symptoms started after a high-dose or long-term EMF exposure, that they actively tried to avoid EMF sources and that they mostly could affect the EMF environment. A minority had sought medical attention, been diagnosed by a physician or received treatment. Exhaustion syndrome, anxiety disorder, back/joint/muscle disorder, depression, functional somatic syndrome and migraine were found to be comorbid with EHS.