I feel like fainting, why is that?

Well I was going to turn around and I accidently hit my elbow on the wall. Kind of hard but I fet like faiting for some reason. It's not the first time, when I was younger I was riding my bike when I accidently hit my knee with this pipe. Like it kind of hurt but I lost balance of my bike sense I felt like fainting I had to sit down until my knee stopped hurting then I went off riding my bike again like nothing happened.

from your desceription, you are saying that you feel fainting while you are hurt. the reason why we feel pain is because there are many nociceptors through your body which can detects signals in forms of chemical such as bradykinin release during a cut, physical such as a hit and thermal such as heat. once those receptors are activated the signal will proceed to the ganglian root then to the spinal cord lamina I region, it then intercross to the ventral horn and then toward your brain via both the spinothalamic pathway and spinoreticular pathway so that you have the preception of "pain" and you might be able to localise where the pain is then you will produce a response such as avoiding from the pain source. substance P is believed to be the neurotransmitter for the nociceptive signals, when this signal gets to intense, another neurotransmitter is released which will act as an antagonist for substance P, i forgot what this natural substance from our brain is called but i know that opiods are susbtance P anatagonist such as morphine so that you won't feel pain.

with this background knowlege, the possible reasons for your symptoms can be physiological or psychological
1 there are may be more than one region in the spinal cord which also reacts with substance P so that another signals to transduced to the brain which causes you to feel faint as well as pain
2 the substnace P antagonist might cause the faintness if you only feel faint when the pain is very intense
3 you might have had an accident in your childhood, for which the traumatic memory resided in your brain, thus whenever the pain is arouse, you feel faint becuase you are extremely scared

all my suggestions are only guesses

See a doc.

I think you just don't like pain, that's all.

This maybe either hypoglycemia or anaemia....
See a doctor 2 run a few tests & pls tell us the results...
We wanna make sure that u r Ok...
I hope u'll be better soon...

maybe you're low blooded. its better if your'll see your doctor

If this continues, see a doctor. This used to happen to me when I got up fast. I began exercising regularly, and it went away. It used to feel like a 'blood rush' followed by dizziness. I also saw white spots (what they call stars) for a few seconds.

It could be a myriad of reasons, but the most likely is that it's just your body's way of dealing with pain. You should probably get your blood pressure checked, though, just to be on the safe side.