Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Dry Mouth ?
    ### Response:
    Dry mouth is the condition of not having enough saliva, or spit, to keep your mouth wet. Everyone has dry mouth once in a while -- if they are nervous, upset, or under stress. But if you have dry mouth all or most of the time, it can be uncomfortable and lead to serious health problems.
    