Thanks for writing to H.C.M. for query.
I have gone through your clinical history regarding regular phlegm and mucus from throat and nose. Your tonsillectomy
had been done about 12 years back.
Considering your symptoms and past history of illness it is most likely upper respiratory tract
infection with some allergic involvement. To manage this you should do following test-
(1) C.T.scan of paranasal sinuses
(2) Culture and sensitivity of nasal discharge.
(3) X-Ray chest - P.A. view.
(4) Blood- CBC, blood sugar- F. & P.P.
Tharough examination and there co-relation with investigations is necessary for establishing correct diagnosis, which can be plan for treatment accordingly.In the meantime you can take steam inhalation and anti allergic cough