I had an echo/cardio stress test today for recent attacks of sudden chest/back/arm pain following sudden chest pressure/dizziness. But immediately after the test while still lying on my back I felt like I just needed to clear my throat so I sat up, and began coughing up clear mucus so severely that 3 technicians and a doctor had to catch me and hold me up so I wouldn t slam onto the floor. I ve never had a cough like that in my life. It took a good 20-30 minutes before I stopped throwing the slimy mess up which wasn t that much compared to the serverity of the cough. Why did that happen?