Sternum cracking, pain in side of body and in ribs.

Hello,

For the past month or two i have noticed some problems have been coming up that seem to be getting worse. It pretty much started when i inhaled deeply and my sternum will crack like when you crack your knuckles. This only happened every 10 to 15 minutes when i would inhale deeply. As time has gone by iv started to notice that it is starting to turn painful and now my ribs get sore and the side of my body gets very sore. It feels like i have slightly pulled or torn the muscles on the side of my body, and it is mainly on the right side but most of the time i dont get pain on the left side. It doesn’t actually feel like iv torn my muscle but its that same kind of pain and very minor. It pretty much only gets really sore when im sitting down for long periods of time, like when im using my computer or something like that.

Im 17 turning 18 on december and i used to be a high performance gymnast and did gym for 8-9 years. I trained for 4 hours a day so i got quite a lot of exercise until i quit at the beginning of this year because i was having bad lower-back problems (disk buldges was the problem) and couldn’t go on anymore. Iv seen doctors about my back many times but its not really something that can be cured nor does it go away because it has always come back for me.

Now that i quit gymnastics, i now do circus arts, i dont get as much exercise as i used to when i was doing gymnastics. I probably now get about 60% less exercise than i used to when I did gym.

I started smoking about 4-5 months ago and i do notice now that i am not as fit as i used to be, even though i smoked only about 4-5 cigarettes a day. But now im starting to stop because i know how terribly unhealthy it is and makes me quite worried about my own health.

I went to see the doctor about my sternum cracking and she said it was completely normal. But now it is getting worse since then and i dont know what is causing it. What makes my sternum and ribs feel really sore is when im sitting at my computer. Me and the doctor come to the conclusion that it is happening because when i sit at my computer for long periods of time (8 hours) i am very slouched over, but when i sit up right with a good posture i still get pains, but not as badly as when im slouched.

Im quite worried about these pains in my sternum, back and ribs and it makes me quite worried. And being worried about this kind of thing does not help my anxiety problems either, which is why I come here to discuss it. Do I really have anything ot worry about? Are these kinds of pains normal or are they not? Has anybody els had the same thing and does it stay or does it just go away?

Thank you