Can an 18 year old have a heart attack? Ever since I was little, I have always had chest pain, sometimes I pass out, makes me dizzy, numbness in my left arm. The chest pain will last from a few seconds to 30 minutes, then goes away, however it happens mor

Congenital anomaly. Aortic root, aortic valvular disease aberrant coronary anomalous coronary origin but as another has noted: Cocaine and other drugs of abuse are more likely.
The . The combination of chest pain, left arm numbness and increased symptoms when you are more active seems to suggest a possible cause of your symptoms being related to your heart. I think it would be reasonable to pursue testing which may be sensitive enough to pick up a subtle problem - perhaps a congenital abnormality of a coronary artery or a predisposition to a marked tachycardia (rapid heart rhythm). A stress echocardiogram or a holter monitor might be of value. I would recommend discussing this in person with your heart specialist or another cardiologist.