At approximately 8:00pm last night I noticed an intermittent pain in the left of my chest. If got gradually worse and I started sweating (possibly through panic though). My dad gave me two painkiller tablets and said he would call an ambulance if it didn't stop once the tablets had had time to take effect. He sat in the room as I tried to sleep and must have left as I woke up at around 8 this morning. I said that the pain was still there (more like a dull ache now) but we didn't do anything. It hurts to breathe in deeply and my back and neck feel sore. I'm 14 yrs od, male, roughly 5"7 and nearly 9 stone. What is it and is it dangerous?