i get chest pain when two ribs pinch a nerve. things to avoid:

don't do the cobra in yoga.

don't try to sprawl across the bed of the pickup trying to reach something that is just a little too far away. get a ladder and climb up in the pickup.

when i get this i just have to take very shallow breaths until i can get to the chiropractor, or do other yoga poses if my body will allow it. the yoga will do the same thing the chiro does if you listen to your body about what hurts and what doesn't. & don't do what hurts.