Hello. I am 38 years old.  I have been dealing with this for over ten years.  May be a long story, but will skim through this from the begining of my story...  On here this morning trying to find the name of the diagnosis the Dr. finally gave me as I am going through it again...  Was not diagnosed with costocondritis, but very similar.  Put up with abdominal pain for almost 3 years before being diagnosed as I was a young single mom & couldn't miss work just because I did not feel well.  Then one morning it was too much & my friend thought I was having a heart attack, took me to the ER & told the Dr. I wasn't leaving until the could tell us something useful. The ER told me two things:      1-  I was passing gall stones...  This was due to my eatting foods with higher fat levels than I was used to & my body did not know how to process that much fat.    The easiest & cheapest way to diagnos gallstones is an Ultrasound...       2-  My chest pains- sternum, ribs, down both arms to the elbos...  Was \ is triggered by STRESS!!  Studying for exams in nursing school, I would have an episode.    Not getting enough sleep.    Major change of diet.    Even worrying about my Dad's health issues all trigger episodes.      Any kind of stress can trigger an episode: physical (accident, being sick for more than a week, lack of sleep)                                                            emotional (family stress, school pressures, death in the family, worrying about everything)     With all the pressures we have today, for kids to excell at everything, to grow up so quickly, to help with raising their siblings & running the house, what used to be a diagnosis for middle-age, high powered executives is now way too common in every age group.      If you get a little bit of warning before an episode kicks in, write down how you have been feeling for the past few days...  depressed?  worried?  too busy studying to exercise like you used too?  working more than normal?  not working as much as normal?  been ill?  new medication?      When I have a severe episode, one of those where I can't even get comfortable enough to sleep- the lack of sleep only makes it worse- my most effective thing to do is to crawl in the bath, with the water as hot as I can handle.  IF YOU TRY THIS...  Have a cold glass of water with you.  Have someone else home with yoou who knows you are in the tub, or have a phone with you.  Having the water that hot will thin your blood temporarily, so if you just pull the plug on the tub & stand up, You May PASS OUT!  I suggest that when you are ready to get out of the tub, drain the water & just sit there while the water runs out.  Drink some cool water throughout your bath.  If you feel dizzy when you stand up, either sit back down & wait a minute, or slowly get out of the tub & sit down of the floor with your back against the side of the cool tub.      Sorry for being so long winded, but after ten years, this is what works for me.  I still have episodes, but once I figured out my warning signs I can usually keep from having a full blown attack.     Good luck.  Hope this helps you.     If you end up going to the doctor, or the hospital you may want them to do an ultra sound if you want to rule out the gallbladder issue.        Good luck to all of us who are over stressed!  Try to relax & eat as well as you can.