What Causes Aching In The Arms & Legs?

hi, i am a 15 year old girl. i've been feeling light aches in my arms and legs. i thought it was because of the amount of sleep i'd been getting, about 8 hours. but i also recognize the feeling, and thought maybe it's growing pains. i am of decent size i would say, about 5'3 in height and 120 in weight. any idea what it could be?