Hello and welcome to HCM, Post nasal drip is a feature of sinus infection or sinusitis. The history suggests that you were suffering from sinusitis. Lymph nodes commonly enlarge in response to infections. Poor oral hygiene can also cause enlargement of local lymph nodes. However, inorder to know the cause of lymph node enlargement, an aspiration cytology of the lymph node needs to be done. In this investigation, cells are aspirated using a needle, spread on slide and stained. the cells are examined under the microscope. This investigation will identify whether the cells are neoplastic or non-neoplastic. Smoking causes non-productive cough and dryness of oral mucosa. You need to quit smoking to get rid of oral symptoms and coated tongue (hairy tongue). thanks and take care Dr Shailja P Wahal