Recently, a report by the National Academies of Sciences (NAS), USA has found directed microwave radiation to be the plausible cause of the Havana syndrome. 

• In late 2016, USA diplomats and other employees stationed in Havana (capital of Cuba) reported feeling ill after hearing strange sounds and experiencing odd physical sensations. 
• The symptoms included nausea, severe headaches, fatigue, dizziness, sleep problems, and hearing loss, which have since come to be known as the Havana Syndrome. 
• The more chronic problems suffered by Havana personnel included mainly vestibular processing and cognitive problems as well as insomnia and headache. 

• While the symptoms have resolved for some of the affected employees, for others, the effects have lingered and posed a significant obstacle to their work and affected the normal functioning of lives. 

Source: The Hindu