What Causes Bumpy Red Spots On The Upper Body?

hey ok so like on my back, between and on some parts of my breasts i have these weird bumbpy red spots. and i have some on my sides. i dont know what they are? there not ache like there just not i know that cause its different but its bothering me cause it doesnt look good it just looks weird like it kinda looks like a rash but i just got them recentally in the middle of this month and i just want them gone. help?