Call your local emergency number now if pain is new, severe, lasts more than a few minutes, occurs at rest, or comes with shortness of breath, sweating, nausea, dizziness, faintness, a fast heartbeat, or pain spreading to the arm, jaw, neck, back, or shoulder. These can be heart or lung warning signs. The
CDC lists shoulder or arm pain with chest discomfort as possible heart-attack symptoms.
Only if the pain is clearly triggered by a recent muscle pull, is tender when you press or move the shoulder/chest, and none of the warning symptoms above are present: rest the area, apply a cold pack wrapped in cloth for 15-20 minutes, and consider paracetamol/acetaminophen if you normally can take it. Seek urgent assessment today if it persists, recurs, or you are unsure.