I have chronic post nasal drip which causes me to cough and hack . It makes a tickle in the back of my throat sometimes or it just drips and causes me to cough it up. I don't have a cold or sinus infection,I do have hay fever, but that usually subsides with medications. i am finding that nothing seems to help stop[ this problem for a long period of time. Claritin helps for a couple of hours, Benadryl helps but as soon as it wears off its back again. I've been used to having PND for years, but there was always a reason. This time it's continuous...everyday and night with maybe a few hours in between when it stops. It actually started being chronic last Spring...then it seemed to go away at he end of June and during July. But two weeks ago it returned with a vengeance. Please what can I do???