plz help me ..Daily i suck out the secretion from the back of the nose and bring out from the mouth without any preceding act of cough, it is sputum but without any cough.sometimes it comes direct from my throat and sometimes from back of my nose.it is very sticky and white substance and somtimes hard to suck also.plz advice me what is excatly this problem.??how it happend and whats its cure.