Hi. What you are describing is called as a post nasal drip. We on an average, in a normal situation produce about 1 to 1.5 litres of nasal secretions/mucous every day. This mucous is useful to trap unwanted particles and by the help of hair like cells (mucociliary cells) this mucous is pushed into the throat from the back of the nose. We do not even notice this phenomenon because it happens at a microscopic level. Now, during an allergic process or in response to an irritant being inhaled into the nose, we produce more than usual amounts of mucous and these may be thicker in consistency and when being pushed at the back of the throat begin to get noticable. Sometimes they fall right into the vocal cord region and trigger a sudden bout od cough or more commonly they irritate the posterior part of the voice box as they are being swallowed, leading to throat clearing due to the sticky nature of the fluid. It is not necessary for the sinuses to be noticeably infected or for the allergy to show in the form of sneezes or a runny nose to indicate the possibility of a post nasal drip. Due to the long and deep nature of the nasal cavity, an inflammatory response at the back of the nose or an isolated subclinical sinus irritation is enough to create a post nasal drip. Saline nasal sprays if used 3-4 times a day helps clean the nasal cavity from these irritants and improves the mucous circulation. If the post nasal drip persists, for more than a day or you start having symptoms of sinusitis such as fever, clogged nose, bony facial pains etc then you should see an ENT specialist to evaluate your nasal cavity and start you on medications (mucolytics, anti allergy medications, mast cell stabilizers and if necessary an antibiotic) Do let me know if you have any other questions