My Boyfriend Is Here With Me And Is Having Pain

my boyfriend is here with me and is having pain in his chest (sternum) , back and arms and keeps burping. his left arm is puffy and his fingers on both hands are numb. do you know what this could be? as soon as i rubbed his back he said he felt better. he had a similar episode this morning when he woke up but it passed fairly quickly. i gave him a Zantac 150 thinking it might help and it seems to have. he had a similar episode in church about 10 years ago and had a full cardio exam...everything checked out great. could this just be anxiety?