so i recently came down with the flu, which made me sick for about a wk. I didnt really have a cough untill yesterday. Thing is i dont cough all day long, only when i lay down at night. So my question is this, can anybody please explain to me why, when I'm up walking around, I dont cough, and my nose isnt as stuffy, but when i go to lay down i break out in a coughing attack, and my nose becomes real congested??