I have a condition known as Pectus Excavatum, more commonly referred to as a sunken or concaved chest. I was not born with this - it has developed as I grew up, and is relatively minor when compared to photos you can see online. It is only somewhat noticeable now that I have begun weight lifting and developing more defined chest muscles.
However, something being only somewhat noticeable is still noticeable, and it bothers me. Are there are exercises I can do to fix the problem, or at least lessen how obvious it is?