What can be the cause to have dizziness, dry mouth and bitter cold feet?

The symptoms you describe can be due to multiple causes, and almost none can justify all den together. Dryness and bitterness of mouth may be related to daily habits, such as smoking or talking long followed, situations of fever, diarrhea, states dehydration, taking some drugs, some diseases, such as diabetes, anemia, autoimmune diseases, depression, gastrointestinal problems. Concerning dizziness, do not describe the characteristics of the same, so it is very difficult to know the cause. I same with cold feet. My advice is to see your doctor to do a good clinical evaluation that allows you to reach a diagnosis.