I Have Had Breast Implants for 15 Years; Experiencing a "Sloshing" When I RuN?

This is a not uncommon complaint with Saline Implants immediately after surgery and then again later, years down the road.  At first after surgery, there is air and fluid around the implant.  Patients will say they "hear" and "feel" the implant moving.  Down the road, one of two things can happen.  The breast, capsule and thus the space surrounding the implant can stretch and the implant then moves too much in the pocket.  The second cause is a partial deflation of the implant, usually a slow leak of the valve.  A revision breast surgery can fix this.  Usually, it involves implant replacement with a slightly larger Silicone Gel Implant and sometimes a capsulorrhaphy.  Hope this helps. Good Luck!

    If the breasts remain the same size, the possibility of leak is small.  The air within the implant could be the issue and could be producing this.  Sometimes air and fluid around the implant can cause noise as well.  A surgery may be the only thing to fix the sloshing, but an exam would be needed to verify this.

The sloshing you may be feeling is the saline implant. Silicone implants do not  slosh around.  You may want to switch.

If your implant has been in for 15 years you probably have a saline implant as silicone gel was not available. Sloshing might indicate a slow leak and volume loss, not unexpected after 15 years, and it might be time for a replacement.

Your breasts will age as will your implants. Over 15 years there is the risk that you may have a rupture that may be making this feeling more noticeable over time. Additionally, you can have changes in the breast pocket etc. All of this would need to be determined after an in-person visit with a plastic surgeon.
You should see a board certified plastic surgeon in your area to get a formal opinion through and in-person consultation.
Best of luck!