Genetics, buddy.

It’s just the genes you were dealth with. It won’t hurt to see a doctor and get some x-rays to address any possible serious orthopedic problems in the future, but there’s probably not much that can be done.

There’s a name for it, according to Wikipedia: Pectus carinatum

Have your doctor check you for scoliosis also (curvature of the spine). PT and specialized exercises may be helpful.

It is probably because of the parents you picked. It appears to be genetic because it occurs in families again and again.

Unfortunately, both of these things can sometimes cause problems as you get older. For flat feet you may need orthotics to prevent foot pain, and with pigeon chest you can have problems with your heart and lungs as well as bone structure.

I would suggest you talk to your doctor about it so things can be monitored and addressed if it is getting worse. You can hide the shape of your rib cage with body building, but that won’t fix the problem. Here is a bit more on pigeon chest, and here is something about flat feet.

Cant help but welcome to Fluther!