Sounds like you are in a low-humidity situation. Consider a humidifyer, also be sure you are drinking plenty of fluids throughout the day. A great choice is to have a carafe of your favorite tea/infusion available.
What area of the country do you live in?
What type of heating/cooling is being used in your home? Wood heat dehydrates the air and you too :)
Is your household fully non-smoking? Even traces of secondhand smoke are irritating to tissues. Air fresheners can also contribute to breathing problems.