Lightheaded from practicing?

[greatk82]

During my first tour in Iraq, dizziness while playing was a huge problem. We spent the better part of July and August(130+ Degrees F) with 40 ounces of water per day. This was for personal hygiene as well drinking, eating and heating MRE's. Malnutrition + dehydration + excessively high temperatures + 1st tuba parts in a tuba-euphonium quartet on a beat up Mirafone 186 = dizziness/passing out. Ah, good times.

[greatk82]

It wasn't someone limiting supply. We just didn't have the water. It only lasted a few weeks, but man did it suck. I have a newfound appreciation for water. I still hate the taste, but I drink it at every opportunity. The worst thing was that when we moved to a new hooch in the middle of July, two of our Staff Sergeants had multiple cases of water under their cots. They had been stealing bottles and hording them to wash their hair and soak their feet. We were quite angry. I will not discuss their retribution as I like my job. To make things even MORE fun, I broke my back in August. I was taking copious amounts of percocet and flexerill, both of which severly dehydrated me.

[tubaguy9]

In all seriousness, if you're feeling lightheaded from playing, you should have a thorough physical.

In all seriousness, if you are feeling lightheaded from playing, you're probably breathing properly AND breathing properly is something you usually don't do!

Maybe I'm missing something, but I've never expierienced lightheadedness from playing the tuba(or from running or swimming for that matter).
Hyperventilating can cause lightheadedness. Is it possible to hyperventilate and play tuba at the same time? Is this a good thing?
There are some physiological problems that can cause lightheadedness or worse during physical exertion.
Whats with the bold print, are you yelling at me?

It's not hyperventilating that causes it on tuba...I think the reason it happens with tuba, is that we use so much air, along with us pushing it out in the right intervals, that we don't get enough oxygen to our heads. Therefore, we get lightheaded!
(sounds so simple, doesn't it?)
(in this post, he's getting lightheaded!)

[Captain Sousie]

Actually it is neither too little nor too much oxygen in the bloodstream/brain, it is a thing called 'hypocapnia' and it is brought on by the presence of too little CO2 in the bloodstream/brain. Here is the wikipedia link (I know, it is not the best resource but in this case it was correct and fairly well put) http://en.wikipedia.org/wiki/Hypocapnia

Sou