Hi, I have been feeling constantly thirsty and having a dry throat for the past two days. I have seasonal allergies and take Zyrtec-D only when needed. I eat a healthy diet and haven t changed anything in my diet. I have been taking Monistat 3 Day to clear up a yeast infection. I ve also been using a new mouthwash that has a teeth whitner in it. I don t really know what this could be. I am 35, 5 6, 150 lbs., have mild seasonal allergies, and exercise induced asthma.