Do you have to fast to get your thyroid checked?

You’re likely reading this because you’ve got some concerns over your thyroid health. Maybe your doctor has recommended getting it checked out, or perhaps Dr. Google has brought you here in a panic about the many ways your lack of sleep could be impacting your hormones.

Regardless of why you’re here, we’re glad you stumbled upon us! We won’t bore you with fluff- let’s get right into answering the burning question at hand: do you have to fast before getting your thyroid checked?

Short Answer:It Depends

The longer answer is that fasting may affect certain blood tests but not others – that includes thyroid function tests (TFTs). So if TFTs are all that’s being drawn during testing, there’s no need for fasting.

But like everything medically related- nothing is ever quite so simple!

So now let’s take a deep dive into understanding when and why patient needs to fast before checking their thyroids.

The Function of the Thyroid Gland : An Overview

First things first, what is our thryoid gland and what does it really do?

Our thyroid gland sits on our neck region and consists of two lobes connected by an isthmus(middle part). It produces hormones which help regulate multiple bodily functions from hunger regulation to metabolism control.

Explanation Of Hypothyroidism

If it stops working efficiently due to various factors such as autoimmune disorders , medical conditions or even environmental influences we can experience hypothyrodisim causing fatigue,brittle nails,mood swings etc .


Numerous reasons can lead up tp hypothyrodisim including but not limited to:

  • Autoimmune disorder.
  • Iodine deficiency.
  • Radiation exposure
  • Surgery/Radiation Treatment

The problem with Hypothyrodosim lies in its vagueness since its symptoms largely overlap with other common ailments. Diagnosing the right ailment can be overwhelming to patients and some medical professionals around . It’s for this reason thyroid function tests are recommended.

The Different Types of TFTs

An initial inquiry into checking ones thryoid gland includes an appointment with a general physician or endocrinologist .The doctor recommends performing blood tests known as Thyroid Function Tests (TFTS) based on the symptoms exhibited by a patient during their visit.

There are two types been namely: routine- Standard TFTs and Special Endocrine Studies-TFTs.Regardless both require needle sticks in order to get tested .

  • Routine TFT:
    Includes measuring T3, T4, and TSH levels.
  • Special Endocrine Studies-TFT:

Also measures calculations about Protein binding etc .

Do We Have To Fast For Each ?

Now let’s circle back to our question from earlier : do you have to fast before getting these done?

As stated initially , fasting requirements depend entirely on the type of test being performed.

So here is your yes & no answer :

  • There is technically no need for hcfasting prior to Standard TFts
  • there Is requirement for 12 hour fasting window when undertaking Speciaql Endorine sTFt if instructed by Your Practitioner

Reasons FOR Fasting?

Fasting might become necessary since certain elements present in food can contribute towards inaccurate results being recorded through influencing multiple hormonal chemistries regulating your body functions .

For instance Riboflavin present in meat may falsely elevate thyroxine levels whereas soy intake has been noted I’m interfering With mandatory medicine intakes specifically Levothyroxin sodium.This information although minor plays an important role while taking such labs requuiring dietary restrictions.


Overall, it’s essential that there must always be open communication regarding any concerns patients have about checkups–this way practitioners caqn best determine what kind of tests are needed.

Fasting restrictions put in place for thyroid testing can vary depending on the type of test being preformed during your visit.

So to sum up , always be ready with a list of questions for your doctor, and don’t hesitate to tell them any concerns you have — even if it’s something embarrassing as farting loudly or getting aroused while taking labs– so they can give you the right care sintsead of being too shy about anything.Rest assured- there’s no need to go hungry due to just going in for such routine health check-ups!