From the time I was 5 or 6 until I was in my late teens, I fainted a great deal and had many dizzy spells & "close calls". After EEGs and other testing, a couple of causes surfaced:
- anemia / low iron levels.
- low blood sugar (even a little fruit juice is a big help).
- standing still for too long (actually, related to the low blood sugar & also low blood pressure).
- when my mom brushed my hair the "wrong" way. Yeah -- sounds strange, but if she was too easy, with too slow a stroke, over I'd go. Weird, but true.
None of these were a big deal and diet definitely helped, as did becoming aware of my own body. And, yes, headaches frequently accompanied the other symptoms (especially after I fainted -- then my head REALLY hurt, even if I didn't hit it on anything).
Another common fainting cause is stuffy sinuses (backs up into the ears & it's the middle ear that determines balance). Headaches & sometimes dizziness are frequently caused by being slightly dehydrated, which also occurs during allergy season (along with the aforementioned stuffy sinuses).
Do you need to get to the bottom of this? Absolutely. Is it time to go running to a neurologist or for an MRI or CT scan? Maybe not yet. Anemia is an easy thing to check. Stuffy heads, either because of allergies or a cold, is noticeable.
Keep at it, but don't immediately think brain issues. It's not uncommon -- really.
BTW -- years ago, it was common practice to keep someone awake who had hit their head or was suspected of having a concussion. From what I understand, that's no longer the case and, in fact, frequently rest is recommended. At least, when I got tossed off my horse, hit my head against a stone wall (thank God for good helmets!!) and wound up with a concussion, I was told to rest and take it easy, without sleep restrictions or the old-style, "wake 'em every few hours" approach
Edit to add:
Not sure if anyone's mentioned this to you or your son, but if he feels dizzy he should sit down and put his head down. The trick is to try and get it lower than your heart (like, sit in a chair & put your head between your knees). He doesn't have to sit like that for long, but a minute or so will help. Another help is to not stand totally still for too long. Even bending and straightening his knees will help with his blood circulation. Hang in there!