Ask him to describe exactly how he felt before it happened. Did he have any tingling in his hands? Did he smell anything funny, or see any flashing lights? Most importantly, did he have a headache last time it happened?
In my case, when I fainted, I would usually feel a humming tingle in my head. My hands would tingle, and then darkness would slowly close in, starting from the edge of my vision. Everything felt woozy and dream-like. I usually had about thirty seconds before I lost conciousness, giving me time to sit down before I fell. Once or twice, though, I hit the ground without even realizing it was about to happen.
When I started fainting once a month or so, I decided I had better have it checked out. I had a couple of brain scans, one of which, I think, was called an ECT. (In which sensors were placed on my head, and then I had to fall asleep.) They also performed a CAT scan. They also tested my blood sugar, and tested me for epillepsy. When these showed nothing out of the ordinary, they moved on to my heart.
I had an ECG done, and they hooked me up to a heart monitor which I had to wear for ten days. If I felt faint, I was supposed to hit the “record” button. Unfortunately, I didn’t have an “incident” while hooked to it, so they put me on another one which was a continuous 24-hour record. They found that I had a mitral valve prolapse-- a relatively mild condition, which just requires me to take a pill every day to keep my heart in rythym.
Thank God I have insurance, else these tests probably would have been monstrously expensive. There was a two month period where I had a doctor’s appointment at least once a week.
My sister, grandmother and all of my aunts also faint, but in them, no cause has been determined, and the doctors seem to be unconcerned about it. “Sometimes, people just faint,” one of them told me with a shrug.
I never had headaches when I fainted, so if he is having them every time he does, I might get it checked out, but otherwise, I wouldn’t worry too much yet. (IANAD-- this is only my opinion.) See if it happens again, and try to establish a pattern. Make notes of where it happened, what he was doing, if it was very hot/cold, if he smelled anything or saw any flashes of light, or if he was under any pariicular stress or pain. (The doctors will want to know these things if you decide to take him.)