My nipples are always puffy but when i get cold or have my shirt off in the morning there back to normal size

I have had this since i was around 10 or 11 and i am 15 now my nipples are always puffy but when i get cold or have my shirt off in the morning there back to normal size for about 10 min and then it comes back and it hasnt changed or went down or nothing in them years i had it i am wondering if any body knows how to get rid of it or atleast make them go down