Hi! Everything you described about your son sounds like what I have been going through since I had mono. I go it in high school, and ever since then I have had muscle pain, extreme fatigue, excessive daytime sleepiness, lack of concentration, etc. For years I went to numerous doctors, specialists, nutritionists, chiropractors, you name it! I suffered for about 18 years. I actually thought I might have muscular sclerosis for a while.
Finally, my doctor sent me to a neurologist and I too had a sleep study (overnight and MSLT Multiple Sleep Latency Test). I was diagnosed with narcolepsy. The best thing to do is get the sleep study. I wish I would have sooner, but I did not have a clue! For years I was "just lazy", or "the dizzy blonde." It was very frustrating! As far as the feeling of fainting, it could be cataplexy. I am not a doctor and please do not take my word as if I were. But, you can get some really good information on the intranet about narcolepsy, cataplexy, and sleep studies. Just make sure the website is reputable.
I just want to commend you as a parent for looking further into this. My mother always just thought I was lazy. Your son is a very lucky guy to have such a cool, concerned mom!
Hope this helps a little! Good luck.
Hi Lisa512, how is your son doing? I do understand how concerned you might be regarding his excessive sleep because at this age usually he should be more actively participating in sports and doing well in his studies. Did he suffer a long-standing illness recently or is he been under stress for not doing better at studies. Sleep apnea can be thought about as it can cause him to wake up a number of times even if he is not aware at nights making him really feel tired, unrefresshed and not well oriented to his daily routines. It can also lead to poor concentration in studies as he may feel several bouts of head nodding due to sleep depravation. It is good he is due for sleep study. You may get further investigated on consultation with your physician. Do update on his progress and take care of him.