Brief Answer:
Xerostomia & increased susceptibility of pedal area for edema accumulation

Detailed Answer:
Hi.
Thanks for your query.
Noted your Medical History of diseases, Current Medications and allergies; had hysterectomy 3 days ago.
Received a steroid to prevent nausea/vomiting - still getting sick, drank more water yesterday than you think your have in a day.
Wants to know 2 things: How long will make you feel dry and why is still edema around ankles...

The reason for dryness (Xerostomia) is usually not a steroid but may be some other medicine or anxiety. Please tell me or discuss with your Nurse which medicines have you been given in the last 3 days. Another possibility is local condition of the mouth and the throat that may not be really explained every time - sub-clinical inactivity or hypo-activity of the major and minor salivary glands in response to unknown factors. This usually take a few day the moment you start taking near normal diet, liquids orally as an activating factor.

Secondly since you have already been under treatment for hypothryoidism, the tissues around ankle are more sensitive for development of edema. Excess of sodium can also cause edema (Normal saline or Ringer's that must have been given in peri-operative or post-operative period). Other reasons can be like anemia, hypo-proteinemia.
Elevation of the legs alone suffices in most of the cases to reduce edema.
Stoppage of any medicine known to cause dryness of mouth or the reduction of anxiety can make the mouth to be dry. Or if there is a local condition of the mouth and throat that needs treatment.

I hope this answers your query, please feel free to give feedback and ask for further relevant queries if you feel that there is a gap of communication.

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