Hi there. I am a 35 year old female 5'7 155 lbs with a 7 month old baby delivered by cesarean. I have had shortness of breath that worsens with physical exertion since the last month of my pregnancy but am otherwise in good health. The last 2 months it has been getting progressively worse to the point where I have to catch my breath sometimes in conversation. I am taking domperidone to increase my breastmilk production and have been for 2 months. I have been to the ER where I have had an ECG, ct scan, x-ray and bloodwork, as well as a pulmonary function test. All results were within normal ranges except my oxygen levels in my blood were low - however the test was taken peripherally, not through a central line. Also, my resting heart rate was 118, and when I did a stress test, within 2 minutes my heart rate was at 200. They are sending me for an echocardiogram next. Do you think this could be adult onset asthma or a reaction to domperidone or is it my heart?