That can be frightening when symptoms arise out of the blue like that. It's happened to me a few times and it's been such a relief when I've discovered it was nothing serious, either stress or electrolytes being out of balance. I drink a few coffees and green teas a day, which are diuretics, so I have to be very careful to stay hydrated.
It turned out to be exactly just that - electrolytes. But still, this was a few years back, so I am much more cognisant of what my body needs and how to nourish it properly.
I do not drink coffee or tea, or generally, anything containing caffeine, but I am the type of person who can't drink water without a splash of lime juice in it. :)
A few episodes like this will definitely make you pay closer attention. I was hiking in higher elevations the morning before this happened to me for the first time. It was frightening. I caught a plane home later in the day and then the episode hit after I landed—extreme nausea, pain down one arm, cold sweats, and pain in my neck (thyroid). After a trip to the ER they told me my electrolytes were off balance. Probably due to hiking, flying, and coffee/tea. I know now when I begin to feel the slightest symptom coming on to hydrate immediately.
best way for electrolytes intake is sea salt
cristals on your tongue , let it melt and then drink water.