What Causes Sudden Weight Loss, Dry Mouth And Frequent Urination?
Tests
Detailed Answer:
Sorry to learn about your bothersome symptoms.
HCTZ itself can cause frequent urination. Consequently you could feel thirsty too.
However, there are some medical conditions that can potentially cause these symptom such diabetes mellitus, diabetes insipidus and high blood calcium to name a few.
When I see someone like you in my practice, I typically order the following blood tests in addition to a detailed physical examination:
CBC (Complete Blood Count, also known as Hemogram; includes Hemoglobin, WBC and Platelet counts)
Electrolytes (Sodium and Potassium in particular)
HbA1c (Glycosylated Hemoglobin = your last 3 months' glucose average). Also known by other names such as GlycoHemoglobin or Glycated Hemoglobin or A1c
Liver function tests (SGOT , SGPT, Albumin, Bilirubin, Alkaline Phosphatase)
Kidney function tests (BUN, Creatinine)
TSH (checks your thyroid)
Free T4 (this too checks your thyroid)
25 hydroxy Vitamin D levels (ideal range 40 to 60 ng/ml = 100 to 150 nmol/liter)
Calcium
None of these tests require any fasting and can be done at any time of the day.
Further tests such as those for adrenal insufficiency can be planned based on results of the above tests.