I am 18 years old and since i was in the sixth grade i've had these 'hot flashes', they come and go and i will go through lengths of time where i dont have any at all and other times where i have them frequently. they are back now and they started up in mid december. i probably went almost a year without them. what is causing it? i feel like i'm gonna come down with a cold cus i get so hot. it dosnt matter what time of season it is. what is causing it? anything i should look into? i've had cat scans and MRI with and without contrast and for other things but it was fine. could i be unconsciously triggering them?