Please describe the differences in symptoms in cardiac related dyspnea, asthma related dyspnea, and anxiety related dyspnea?

May be identical: This sounds like a homework question, and i trust your instructor will let you know that that the symptoms (what the patient says) are likely to be identical -- "i'm having trouble getting my breath." the signs (what the examiner sees) will be quite different. Cardiac, may be worse after lying down; asthmatic may be worst breathing out; anxiety take a history.

Dyspnea = Dyspnea: Dyspnea is dyspnea. In other words, dyspnea is just medicalese for shortness of breath. What's more important is to determine the cause of dyspnea. But the symptoms will be similar, eg shortness of breath. So you need to go see your family doc for proper evaluation. With that said, dyspnea related to your heart might be aggravated by activity whereas asthma might cause wheezing just stiing still.