My son is 17 years old, 6 3 ,160 lbs. Out of the blue he got a pain in his upper back that quickly moved to his chest. It is much worse if he is standing, and worse still if he trys to take a deep breath. He has no fever, no fast breathing, his color looks normal and he has no numbness or tingling. He last ate around noon and ate at mcdonalds. He has no history of heartburn. What do you think?