I had blood taken today, started fine then just stopped flowing. As tech tried to continue I got extremely dizzy, vison got weird and my hearing sounded like amplifiers in them. They gave me water as I was very hot. My throat got sore an Ihad a hard time swallowing the last of it. It felt like a lump in my throat. In all probably lasted 6- 7 min. Finished taking sample in other arm all was ok. I have never had any problem giving a blood sample or ever felt as I did today. It really scared me, and the tech said I had I not gotten better soon, they were thinking of calling an ambulance. What do you think