My left arm is hurting it feels like my vein s gonna explose. it started 6 hours ago. no swollen?

Needs examination: Arm pain is difficult without an examination. There are a variety of causes - e.g. neck or shoulder problem or referred pain from the chest. Best to see a doctor. See a doctor urgently if the arm is weak or you have chest pain or shortness of breath.

Painful arm: May be clot in artery ( cold) or vein , may be musculo-skeletal tendonitis or may be from cervical disc ( numb tingling , decreased strength) but would go to ER to evaluate. Motrin may help but still need to assure that it is not clot therefore go to ER .