Q. Can I drink water while fasting for a thyroid profile test?

Hello doctor,

Since the last 10 months, my periods are very irregular. I get periods only once every three to four months. I am on treatment for abdominal TB since the last one and a half years. I take Sompraz D20 on an empty stomach in the morning. I take Duonase nasal spray (two puffs in each nostril) twice a day. I take Immunace Forte after lunch and Libotryp at bedtime. So, why are my periods not regular? Is this a side effect of my medicine or could it be due to a disease? Recently, I was also prescribed Uprise-D3 (60000) once a month for six months. My recent 25-OH vitamin D total is 21.1 ng/mL. I also have sudden weight gain. My weight in the last one and a half years increased from 125 lbs to 178 lbs. I also have a chronic nose block.

Thank you doctor,

For prolactin test, we need to fast for 10 to 12 hours. Am I correct? And, am I allowed to drink water during the fast? Also, which thyroid test am I supposed to undergo? Being an unmarried female, I do not think I require an AFB test. What is your opinion?

Thank you doctor,

For T3, T4 and TSH tests, do I need to fast? If yes, then can I have water during the fast? And also, I have not understood what you mean by second-day menstrual blood AFB test. Is it a blood test? Is it to be done with fasting? Please provide me the full details of this AFB test.

Thank you doctor,

Is prolactin blood test to be done during periods? Or, can it be done at any point of time in a month?

Hello doctor,

Thanks for replying.

How about free T3, T4 and serum TSH blood tests? Can they also be done at any point of time in a month?