Waking foggy-headed and with the room spinning on 26 December is surely not an uncommon condition. Who among us hasn’t felt the effects of overindulgence on Christmas Day?

These were my immediate thoughts when I rose in such a state in my parents’ house in Dublin two years ago. An hour later, the room continued its relentless swirl, nausea was building and it was becoming hard to stand. So far, so Christmas hangover. I remained in bed and waited for things to blow over. They didn’t. Gradually, family members stuck their heads into my childhood bedroom and wondered if everything was OK. I could only say that I felt quite strange.

After a couple of hours, I thought I was over the worst, so I joined my mother, sister and wife in the kitchen. Moments later, they watched on helplessly as I vomited in the kitchen sink, a silent bond created between them.

This process repeated itself several times over the next day, so I visited a doctor. The GP diagnosed a case of vertigo: not any Hitchcock-infused vision, but dizziness and nausea, usually caused by inner ear problems. Often this lasts only seconds, but there can be more prolonged incidents. I was prescribed medication to restore order.

The wider oddity was that, at the time, I was working as a producer on a podcast documentary for BBC Sounds called Havana Helmet Club, investigating Havana syndrome – the 2016 case of mystery brain injuries affecting CIA agents and US embassy officials in Cuba and farther afield.

I had spent the previous year researching all aspects of this strange story: starting with the array of symptoms the patients had begun experiencing, seemingly out of nowhere. Most reported hearing piercing sounds in their homes in Havana, followed by overwhelming headaches, dizziness, nausea and, eventually, lasting brain trauma. There was speculation about Russian microwave weapons and jokes about an “immaculate concussion”. Politicians, scientists, diplomats and security experts argued endlessly about it. Some claimed people had simply imagined it or overreacted to the sound of crickets – suggestions that the victims were rather hostile to. Doctors explained that even if there wasn’t a weapon, other triggers – physical and mental – could cause a dramatic reaction in the brain.

Shortly before my own incident, I had been listening to an interview a colleague had done with a neurologist. The doctor was talking about how, when you become aware of a certain part of your body, your mind can then overly focus on it. If you’re told you have a family history of heart disease, for example, you might suddenly start noticing how you feel out of breath walking up stairs. In the weeks after listening to this, I had occasionally noticed mild head rushes when I bent over or stood up quickly.

In my vertigo-addled state, I attempted to explain all of this to the doctor. I wasn’t claiming I had been dragged into a dastardly spy plot. More, I wondered if somehow I had imagined myself into sickness. Could something a person had read about take possession of their body? When I finished this spiel, she looked at me politely, said, “Right, yes,” and explained it wasn’t an unusual affliction. The pills should do the trick after a week, she told me, and if it happened again I would need vestibular physiotherapy.

She was right, of course, and it passed relatively smoothly. But it did make me think of everyone who had been caught up in the case of Havana syndrome. As well as needing care, many were consumed by a need to know what had happened to them. My illness was minor, but I could see how easily such thinking can take over when you get struck down out of the blue. The list of causal factors for vertigo and vestibular disorders includes everything from lying down to standing up, air travel and much else in between. Most dismayingly for someone in their 40s, it “becomes progressively more common with age”. We are where we are.

Rather than go down the rabbit hole, I decided it was better just to be grateful that my bout of ill health had occurred the day after my big Christmas dinner – even if the medication did mean I could only sip non-alcoholic “champagne” on New Year’s Eve. Perhaps a fate worse than vertigo itself.