Tests You Need and Optimal Levels as a Hypothyroid Patient

Originally published on 11th March 2016
Last updated on 24th November 2023

As a thyroid patient, the below blood tests are recommended to get the full picture of what’s going on. If you still have symptoms, despite being on thyroid medication, explore these. If you feel well on your thyroid medication, monitor these regularly.

Really, everyone should monitor their thyroid levels. 

You may have to repeatedly ask doctor or try a few different types of medical professionals before you find one who will do all of them. Alternatively, you could order them yourself if this is an option. I have linked to some places below, next to each test.

Please also check out “Be Your Own Thyroid Advocate”, my must-read thyroid patient book. If you find all of this confusing, I promise you won’t after reading it!

The results you should be aiming for are also listed where possible.

The Essentials: A Full Thyroid Panel, to include as many of these as possible:

TSH

Thyroid Stimulating hormone. It gives an indication of thyroid hormone levels but doesn’t actually measure them as it is a pituitary hormone and not a thyroid hormone. Read more here. It serves as an average read out over the previous four to six weeks of your thyroid levels.

Free T3

A measure of the active thyroid hormone, T3.

There are binding proteins that attach to thyroid hormones to transport through the blood vessels, to cells all over our body. When they reach the cells, only the unbound ‘free’ hormones can actually be used by the cells. Therefore Free T3 levels (and Free T4) are important to monitor. It’s important to be aware that Free T3 and Free T4 are different to Total T3 and Total T4. Make sure you check ‘free’ levels.

Free T4

A measure of the less active thyroid hormone, T4. The body should convert T4 to T3 but doesn’t for a lot of thyroid patients.

Reverse T3

(see here why testing Reverse T3 is often controversial and why I’m dubious about whether it’s truly useful. I lean more towards ‘no’, however, you will see other thyroid resources suggesting we must have it checked.)

Thyroid Peroxidase Antibody/ies (TPOAB)

This measures the amount of thyroid attacking antibodies in your blood and is used to identify an autoimmune disease like Hashimoto’s Thyroiditis.

Thyroglobulin Antibody/ies (TGAB) 

Also used to identify Hashimoto’s.

Related Article: Why It’s Important to Know if You Have Hashimoto’s

Why You Need These

At the very least, you must have TSH, Free T3 and Free T4 tested to get an idea of how you are doing, but also testing the two antibody tests can be very beneficial.

It’s worth knowing that you can order full thyroid panels yourself from online laboratories too. Find a UK lab here and a US lab here. 

Optimal Thyroid Test Results

TSH – Below 2.5. May be close to 0 on T3 containing thyroid medication. More information found here

Free T3 – Upper quarter of the range. More information found here

Free T4 – Midrange or a bit higher. More information found here

TpoAB and TgAB – In range indicates Hashimoto’s is not present or that it is in remission. Over range means you have Hashimoto’s that is not controlled. (UK lab test including thyroid antibodies here and a US lab here.)

Always work with a doctor in evaluating and reevaluating your thyroid hormone levels, keeping in mind your symptoms and overall health as well. We’re all individuals and there is no ‘one size fits all‘, but there are obviously health risks if your thyroid hormone levels, vitamin levels or any others are either too low or too high for an extended period of time. Your doctor should know where they sit best for your health. The given numbers are a guide only. 

Other tests to explore and results most thyroid information sources state to aim for:

Vitamins and Minerals:

Vitamin D – 80 nmol/L or 50 ng/mL. (UK test option here. US test option here.)

B12 – Close to top of range. (US test option here.)

Folate/Folic acid – In the top quarter of the range. (US test option here.)

Ferritin – 70-90 ng/ml, being slightly higher for men. (US test option here.)

Iron, T.I.B.C., Transferrin Saturation – well within range. (US test option here.)

Magnesium – Mid-range or higher. (UK test here, US option here.)

Selenium – US test option here.

Sex Hormone Testing (for: fertility, sex hormone imbalances, PCOS)

Oestrogen, Oestradiol
Progesterone
Testosterone
LH
FSH
Prolactin

For a UK PCOS Blood Test, click here.

This UK test checks almost all of these in one go (minus progesterone).

This US lab checks almost all of these in one go.

Adrenal Health

24-Hour, 4-point Saliva Cortisol Test
8am – Top of the range.
Midday  – Upper quarter of the range.
4-5pm – Midrange.
11pm – Midnight – At the very bottom of the range.

DHEA – Above mid-range.

If your doctor won’t check your adrenals, you can very simply order testing yourself in the UK here. I am yet to find a 4-point saliva test for the US. Please Leave any suggestions in the comments!

Gut Health Testing

Candida (yeast overgrowth) – A UK test for Candida can be found here.

H Pylori

Coeliac Disease – A UK test can be seen here.

Other Endocrine Testing

Diabetes (HbA1c/Haemoglobin A1c/glycosylated haemoglobin) – UK test option, US test option.

Other Testing – these often seem to come hand in hand with thyroid issues

Cholesterol (Triglycerides, cholesterol, HDL, LDL, Non-HDL, Total/HDL Chol ratio) – UK test, US test.

Kidney Function (Urea, Creatinine, Estimated GFR) – UK test option, US test option.

Liver Function (ALP, ALT, CK, Gamma GT, Bilirubin) – UK test option.

Lyme Disease – Find a US test for Lyme Disease here.

Click here for more places you can order your own tests from. 

***

Please find references to optimal results here.

You can click on the hyperlinks in the above post to learn more and see references to information given.