35 m cleared by doctor for cardiac issues, but have acid reflux. when carrying heavy suitcase up stairs feel sob. out of shape? freaked out!!

What tests?: How were you "cleared"? For your symptoms and age, not knowing your risk factors or blood pressure, you should have had a blood panel for chemistries, blood count, and thyroid function. You should have had an EKG, an Echocardiogram (ultrasound of the heart) and a routine treadmill stress test or stress Echo study. If you did have all of the above and they were normal, seek a non-cardiac cause.

Deconditioning: If overweight, sedentary lifestyle, smoking and poor dietary habits can present with SOB on minimal exertion.