RITAK, Hi, sorry about your problem, sounds like that would be very concerning. What kind of sugery was it you had? I ask because possibly you are experiencing post-op symptoms from anethesia etc... It doesn't sound like a thyroid related thing. Have you discussed it with your Doc? I wish I could imput more but if it isn't related to your recent operation, there are so many other things it could be. I hope you Doc can suggest diagnostic tests or possibilities.
Best Wishes.
Sound like GERD (acid reflux disease). When lying down the acid comes back up from your stomach into your esophegus and into your throat casuing cough, irritation and sometimes laryngitis.