Why does my chest hurt?

[bored...]

In the middle of the night I developed chest pain....when I breathe in deeply it really hurts and almost feels like I haven't got enough space in my lungs. It is made worse when I bend down. I'm only 19. I did just start a new job today and was on my feet for 8 hours in a restaurant and was aching all over when I finished. I also had a good session at the gym this morning but felt fine afterwards. What is causing this? I'm a bit freaked out...I have never experienced this before.

[campbellking]

If you're a skinny tall young bloke, you are at risk (a fairly small risk) of developing a spontaneous pneumothorax (partially collapsed lung). However, as you managed all those activities, this is unlikely. If the pain persists, I would pop down to your local A + E to get it checked out.

[saffstar]

You could well have pulled the muscles in your chest. As I recall form biology, you have a strip of muscle between each pair of ribs. If you've pulled these it would hurt a lot when your ribcage expands. My brother's done this to himself in the past. Don't worry too much but you could always call NHS direct (if you're in the UK) or pop to your local A&E if it's bothering you.

[saffstar]

Intercostal muscles! That's what they're called :)