What Causes Numbness In Muscles Along With Lack Of Energy?

yes my son is 16 he is 5'10&1/2 and weights 190 lb he is solid muscle very athletic he has recently started feeling really bad no energy went from being able to do anything to not being able to go up and down a basketball court but one time and his muscles go numb and start to hurt so bad he has to sit down.We found out his blood pressure was high so the doctor put him on meds but at times it wants to go up and down during the day so he feels like crap all the time.We have been to heart doctor who sent us to a kidney doctor who found out that his creatinine level was to high 1.3 and that his kidneys were producing to much something else he said that he was dehydrated he thought that he might tumors causing this but did a ct with contrast and nothing showed up.Our doctor is at a loss at what is causing this .We also found out a while back that his vitamin d was low he takes 5000 mg a day for that. He does have the mono virus in him not active though.My wife has lupus and low vitamin d and a disease called dercums disease.He feels like crap all the time i mean really bad he used to eat like a horse and now when he starts to eat it makes him feel bad he just went from being the life of everything to not able to do much because he feels so bad.Can you please help!!!!!!!!!!!!!!!!!!!!