The mysterious Havana Syndrome first became known in 2016. Dozens of cases were detected among American and Canadian diplomats and their family members in the Cuban capital. According to media reports, the first cases of the syndrome are said to have appeared in 2014 at the US consulate in Frankfurt, Germany. Those affected suffered from dizziness, fatigue, headaches, hearing and vision problems, while some of them lost their hearing permanently.

Since the events in Cuba the symptoms have been repeatedly reported by US diplomats and intelligence officials, including in Russia, China, Austria and most recently in Berlin. Those affected reported nausea, dizziness, severe headaches, earaches and fatigue, and some were unable to work, the Wall Street Journal reported.

Concussion symptoms

Symptoms appear very suddenly. One victim in Moscow was attacked in 2017 while lying in bed at night, GQ magazine reported. The nausea initially made him think it was food poisoning, but then he became so dizzy that he fell every time he tried to go to the bathroom.

“I felt like I was throwing up and passing out at the same time,” the CIA employee told the magazine. The whole thing caught him completely off guard. For example, unlike some Americans at the embassy in Havana in 2016, he did not hear a piercing sound.

The US Embassy in Havana

Experts at the Brain Injury Center at the University of Pennsylvania studied some of the US citizens who were injured in Cuba and published a study in the Journal of the American Medical Association in 2018. In it, the researchers write that the patients have severe impairment of balance, cognitive , their motor and sensory abilities – such as people who have suffered a severe concussion.

But unlike a concussion, the symptoms didn’t go away, they just subsided and then came back more violently.

Psychological suffering of patients with Havana syndrome

In a more recent study, researchers examined a total of 86 US government employees and their family members affected by such symptoms between 2018 and 2022. Compared to a healthy control group, those affected by Havana syndrome reported significantly more frequent exhaustion, post-traumatic stress disorder or depression;

However, in clinical trials researchers were unable to detect changes in the patients’ organs and tissues or in the blood. There were also no significant differences between the control group participants in memory performance or the hearing and vision tests.

Unknown causes

What could be causing the “abnormal health events” also remains unclear. But of course there are assumptions. Specialists from the National Academies of Sciences, Engineering and Medicine in the US expressed one of them in December 2020. They suspect that targeted radio frequency pulses are behind the symptoms.

Other researchers hypothesize that microwave weapons are behind the Havana Syndrome, which US adversaries use specifically against diplomats, intelligence officers and their families. Such weapons using high-frequency radiation have already been developed.

Microwaves operate in the range of one to 300 GHz. The microwave oven that many people have at home heats meals at a frequency of 2.5 GHz. As the frequency increases, the radiation becomes more energetic. With the right device, it can specifically target humans. The rays then penetrate the body to a depth that depends on the frequency, and can cause damage. For example, the US Department of Defense has developed a weapon system that uses microwaves at a frequency of 95 GHz.

Another possibility is sonic weapons – this is suggested, for example, by the fact that some of those affected in Havana heard a piercing sound before their symptoms began. However, other patients with Havana syndrome heard nothing.

There could also be systems that allow attacks in the inaudible range. But little is known about them, except that the military conducted research on them. However, experts have so far characterized their existence as highly improbable.