I am a 31 year old female, and I have been taking phentermine on and off for several months. In the past few weeks, I have had a swooshing heartbeat sound in my left ear. It comes and goes but it mostly occurs when lying down. I feel really tired all the time and even right now my bones/muscles just don't even want to type. I'm having chest pains and lots of pressure on the right side, sometimes it feels like a brick is sitting on my chest. I also the middle right side of my back hurts very often. I went to the Dr. they said my ears and heartbeat was fine. I have read that Phentermine can do things to your arteries and heart, and now I'm really concerned.