Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Dry Mouth ?
    ### Response:
    Dry mouth can cause several problems, including difficulty tasting, chewing, swallowing, and speaking. Swallowing may be especially difficult for those with too little saliva. For example, people with dry mouth may be unable to swallow dry food at all unless they also drink fluids with food.
    