Hi guys I'm brand new to this site so thanks in advance, basically over the last 3 years I have been having what started as a dull ache in my left breast, my gp sent me for an ultrasound which showed nothing. My breast started swelling and causing me some chest pains so my gp sent me for blood tests and to see a cardiologist-both came back fine. Years later and now my breast swells every day, my rib just below my breast is permanently stuck out(never was before) and the pain that hits me regularly is indescribably agonising, the last 6 months my life has been turned upside down, I can't play with my son, I can't take my dog for a walk, I can't do normal household chores, I lost my job etc etc all due to the extent of the pain, I have changed gp's twice and now my new gp is still not doing anything, he keeps saying we have done the tests there is nothing wrong with you. I even referred myself to a counselor in case it was all in my head but she ruled me to be fine with no health anixiety or anything, any advice would be great people as this is literally ruining my life. I should add I am a 31 year old male with no previous health conditions.

Amazing how doctors can tell you there's nothing wrong with you just because they can't figure out what it is.
The first thing that strikes me is that you say it happens 'each day,' which must mean it goes away (to some extent) when you lie down? I would start with something lower down sagging and pulling on muscles and nerves and causing swelling, something non-diseased. I would have tests standing up, and I would have them of your whole torso. I would see yet another doctor, and would shop around through reputation for a specialist in a 100 mile radius, not a GP.
I assume that you have ruled out gynecomastia, which would be in both breasts.

These are all just guesses. It's also possible that you need an MRI or CT, lying down, of your whole torso, first.

I too was told for 30+ years that I had nothing wrong with me, and it was scarring around my sacral nerve, causing zero pain in my back and a lot of pain in my abdomen. Being female, I was tested for all the female conditions and then written off as a hypochondriac. Even a bleeping neurologist failed to remember that the sacral nerve wraps around to the front.

Thanks for the reply, yes it is shocking seems you have been through it yourself too, I will take your advice and see what happens- Thanks again.