Experiencing sharp, tight pain in chest and shoulder blades. No sweating, no nausea,it worsens when standing. The pain gets stronger and weaker but doesn't go away. First started 4 days ago, it stopped for a day came back over the next few days but this time it's been going for about 3 hours. Is it serious enough to visit the ER? I took antiacids with the first episode with no relief, took more earlier tonight and still no relief.