Dry throat is a pretty common symptom, and it can be associated with a lot of different conditions, in addition to the usual throat infections or common viral illnesses.
For example, nasal allergies or chronic sinus congestion might create drainage down the back of the throat, which could give a sensation of dryness or 'tickling' in the back of the throat. Other symptoms that might go along with this would include nasal stuffiness, head congestion, or sneezing.
Similarly, there are many different medications that have, as one of their side effects, dryness of the throat. These include many common over the counter medications. If you have recently started a new medication or change the dose of one of your medications, this might be the cause of your dry throat.
Rarely, dry throat is a symptom of a serious medical problem, such as Sjogren's syndrome, which is an autoimmune condition which affects the production of saliva in the mouth.
I would start by setting up an office appointment with your primary care doctor
. They will be able to perform a thorough examination, review your list of medications, and looks for a cause for your dry throat symptoms.