Havana syndrome, largely discredited medical condition reported among U.S. diplomats and other government employees stationed internationally. Havana syndrome was first publicized in 2016 following reports of an unidentified condition in officials at the U.S. embassy in Havana, Cuba.
Reported symptoms of Havana syndrome include tinnitus (ringing in the ears) and headaches, often with a sensation of pressure concentrated to one side of the head. Individuals commonly claimed to hear loud piercing noises at night, and some reportedly experienced bloody noses, insomnia, nausea, and vertigo. In severe instances, blindness, cognitive impairment, hearing loss, and memory loss were reported. Symptoms emerged suddenly and in many instances were associated with hearing a loud noise.
By 2023 an estimated 1,500 individuals who worked for the U.S. government had been affected by a host of seemingly related symptoms, supposedly the result of Havana syndrome. Extensive research, however, including brain scans of affected persons, provided no clinical evidence supporting the existence of Havana syndrome. By 2024 most cases had been linked to other medical conditions and previous injuries (e.g., traumatic brain injury).
The legitimacy of Havana syndrome is contested. U.S. politicians and government officials have claimed that the syndrome was the result of sonic attacks on embassy staff by foreign adversaries. There is no evidence, however, to support that claim. Rather, symptoms experienced by individuals were more likely to have been perpetuated by stress and social factors. In particular, researchers suggested that the phenomenon of Havana syndrome may have been tied in part to group psychology, wherein individuals’ behaviors change when they are in groups, to the extent that behavioral changes influence the spread of afflictions. A documented example of a condition in which group psychology was influential is an epidemic of repetitive strain injury that occurred in Australia between 1983 and 1985.