Cough spasm and post nasal drip..harmful?

Cough and PND: Not really harmful, but treatable to help prevent it. See the Dr. as nasal sprays can help this condition and decrease the cough too caused from the PND.

Reflex: although this could be the beginining of cough variant asthma, it sound like reflec coughing from post nasal drip or gERD- get it checked by your physician.

Depends on cause...: If you are having post nasal drip due to cold symptoms or nasal allergies those two conditions on themselves are not life threatening. However if you are experiencing significant trouble breathing with wheezing, high fever, chest pain then you should be evaluated for more dangerous conditions. If symptoms are mild try to have plenty if fluids and rest.If allergy OTC antihistaminic meds can help.