Havana Syndrome: What's Causing the Mysterious Illness?

Some have blamed top-secret weapons, but the condition could be all in the mind

- By Dr Christian Jarrett. Photographs by Getty Images and Alamy

In December 2021, a former FBI agent previously posted to Guangzhou in China began legal proceedings against the US government. The agent claimed the US Secretary of State and the Department of State hadn’t taken the situation seriously enough when, while in Guangzhou, the agent and his family had begun experiencing sudden headaches, dizziness, nosebleeds, memory loss and nausea.

It was the latest development in a saga that began to unfold in 2016 when dozens of staff at the US embassy in Cuba started describing similar symptoms, often accompanied by an ear-splitting sound and facial pain.

Depending on who you ask, so-called ‘Havana syndrome’ – which has reportedly affected over 200 US staff in Cuba, China, Germany, Austria, Russia and Serbia (there was also a suspected case in Washington) – is caused by a Russian sonic- or microwave-based weapon, or a textbook case of mass psychogenic illness.

The Russians deny having an acoustic weapon that can target the brain. But in 2020, the US National Academies of Sciences, Engineering, and Medicine published a report in which they concluded that “many of the distinctive and acute signs, symptoms, and observations” described by US employees are “consistent with the effects of directed, pulsed radio frequency energy”. And in November 2021, the FBI admitted to having issued a formal warning to its staff about what it calls “anomalous health incidents”.