<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hello. Im sixteen. Im a runner. Started at 13 Cross Country and Track. I guess since i was 12 ive been having blackout spells. I would stand up and my vision shrink, kind of like tunnel vision. a lot like tunnel vision. i would have to stand up straight cause i get dizzy and loose my balance. It also happens when i walk into a different room. Id walk from the living room to the kitchen and just as i get to the doorway i loose my vision and loose my balance getting dizzy. I have fainted once. outside doing yard work. my finger got caught between two small rocks and it took me a while to faint. My blood pressures good. My iron levels are relativley ok. theyre not the best but theyre within a healthy range. These blackouts would happen around 5-10 times a year. Any ideas. those are my only symptoms. when i was 15 i just started getting regular head aches and i cant hang my head cause it feels to heavy that it hurts. it doesnt feel like there is any liquid in my head, its just really heavy. Any ideas or suggestions?  <response>: Hello, I think I know what the problem is in this case. You need to follow the following steps: 1. You need to make an EEG electroencephalogram to define whether you are or not epileptic. 2. You also need to make a head scanner to exclude a brain tumor and a neck scanner to find out if you have any injuries. 3. Another step is to make a magnetic resonance of brain to check the blood circulation of the brain. I emphasize that you need to follow these steps strictly in order to find the answer to your problem and of course a solution. Take care. 