Puffy areolas/nipples - How do i get rid of it? Is it due to extra estrogen or exercise?

Thank you for your question. I'm sorry to hear about your unhappiness.
Yes, it does sound as if you are currently (stuck) in Tanner stage IV of breast development.

As you know, the stages of breast development are as follows:
Tanner I - No glandular tissue is present.  The areola has the same skin contour as the rest of the chest.  This is considered the pre-pubertal phase, and typically is present up to about 10 years of age.

Tanner II - A breast bud forms, with a small area of surrounding glandular tissue and the areola begins to widen in diameter.  This phase occurs approximately between 10 and 11-1/2 years of age.

Tanner III - The breasts begin to become more enlarged and projecting, and the size of the breasts now extends beyond the borders of just the areola.  As the breasts continue to grow in width and projection the areola also increases in size, but its surface contour remains smooth with the surrounding breast skin.  This stage of development occurs approximately between 11-1/2 and 13 years of age.

Tanner IV - The breasts continue to increase in size, but this stage is marked by the nipple and areola forming a secondary mound which projects off the contour of the surrounding breast mound.  It is this projection of the nipple-areolar complex off the breast mound that gives it a "puffy" appearance.  The degree of projection of the nipple and areola can vary from a minimal amount to an excessive amount where it appears that the breast tissue is herniating into the nipple areolar complex.  This phase of breast development typically occurs between the ages of 13 and 15 years.

Tanner V - This is the final stage of breast development.  The breast reaches its final adult size.  This phase is usually marked by the resolution of the secondary nipple-areolar complex mound, as the areolar contour recedes and returns to be level/even with the surrounding breast skin, and leaves just the nipple to project forward.  In this final stage of breast development, the breast may continue to increase in size, taking on a more full and round contour.  This stage of breast development typically occurs at 15 years of age, and later.

If you look at the stages of breast development you can see that this process takes approximately 5 years.  However, it can take longer in some individuals, and less commonly may extend over a period of approximately 10 or more years.  This means that although there is a fairly common age range for normal breast development, Tanner stages do not always match with chronological age.  In addition, it is also important to note that true breast maturity is not reached until pregnancy when hormones once again alter breast development, and prepare it for lactation.

Without seeing a picture of your breasts, it is difficult to offer specific suggestions on what you should do.  In general, I believe it is important to wait until your breasts reach full development, before addressing this concern with a surgical procedure.  It is very likely that when you transition to stage V of breast development, this nipple-areolar mound will recede and become less prominent, or disappear completely.
The fact that you compare the appearance of your nipple-areolar complex to gynecomastia, and state that it appears normal in contour when the areolar muscle contracts, suggests that the prominence of your nipple-areolar complex is mild or moderate and not that severe.  If so, I would encourage you to be patient and wait for this to resolve naturally.
If the prominence of the nipple-areolar complex is not that significant, if the areola is somewhat enlarged and disproportionate with the breast size, and depending upon the shape of the breast and the degree of skin laxity, a periareolar skin tightening procedure may improve the areolar shape and provide a more satisfactory appearance.  However, I would note that this places a scar on the breast that may not otherwise have been needed when your breast transitions into the next stage of development.  In addition, if you were ever to consider this option, it is very important that you seek a board certified plastic surgeon with significant experience in breast surgery to evaluate you and provide you with appropriate recommendations and options.
For those few woman who may experience more severe prominence/protrusion of the nipple-areolar complex that does not subside with further maturity, a surgical procedure could be performed to excise some of the tissue in this region (if it was deemed that a periareolar skin tightening alone would not correct the problem).  However, it is important to understand that excision of breast tissue in this region will divide the ducts that extend from the breast tissue to the nipple and subsequently eliminate the ability to breast feed.

I hope this is helpful.  Best wishes.

It is hard to tell from your questions as to the ideal treatment. Your description sounds like you have slight "herniation" of your normal sub-areolar breast tissue into the areolae, creating the puffiness. The reason it looks "normal" when cold or irritated sit that the elastic/muscular fibers contract, thus tightening and flattening your areolae.
I don't think it is related to extra estrogen or exercise. It is probably related to the internal anatomy of your tissue...it is just a normal variant.
At age 18, be careful of any surgical procedure that mightt interrupt your ductal tissue(for breast feeding) and decrease your normal sensation.
A photo wouldhelp to determine the degree of "puffiness"
Good luck! 

Hello and thank you for your question....As a growing woman issues with the breast can be a very anxiety provoking experience especially when you feel as though your breasts look different than others breasts. First and foremost it is important to realize that ALL women's breasts look different from other women's breasts and ALL breasts are even different on the SAME woman! The important thing to determine is if what you are experiencing is a variant of normal. I agree with my colleagues in that you should potentially wait for a little longer before considering surgery because you are still pretty young and things can still change. However, without seeing photos it is very difficult to tell exactly what your diagnosis is and if it will change with time. "Gynecomastia" is the improper term to be using here because that is when a male has a female appearing chest and this term is not used to describe a female chest/breasts. What I am thinking you may be describing is more like the term "tubular breasts." These breasts tend to be on the smaller end, have puffy nipple areolar complexes, are constricted at the lower pole and have slightly higher breast creases (IMF). Once again the only way to know for sure is through an in person evaluation. I hope this helps and please hang in there! Just know that there is a VERY good chance that whatever is concerning you about your breasts can likely be corrected by a well trained board certified plastic surgeon. I wish you all the best!