Understanding thyroid markers: what are my tests looking for?

In a thyroid profile, we start by looking at 4 main things: your TSH levels, T3, T4, and thyroid antibodies.

The quick ‘n’ dirty explanation of what these are for:

🗝      TSH = Thyroid Stimulating Hormone.

Basically does as the name suggests! It stimulates your thyroid hormone.

If the body recognises thyroid hormone is lagging, it sends out some Thyroid Stimulating Hormone (TSH) to make more thyroid hormone. Having low thyroid function means the thyroid is being sluggish (but! The real question is, why is it sluggish?).

On a blood test this means that TSH will read higher for someone with low thyroid function. Think of it as though TSH is trying to act like a booster. It sees your thyroid levels are low, and wants to drive them up, when really we just need to adjust the reason behind why it’s being sluggish in the first place. Higher TSH on a blood test hints to us that the body isn’t regulating thyroid hormone well.

In a similar vain, if the opposite is happening and TSH is too low, that means the thyroid is already being stimulated enough, so TSH doesn’t join the party, because, (hint: it’s in the name) if nothing needs stimulating, then Thyroid Stimulating Hormone isn’t going to come to play. This example can be seen in someone with hyperthyroid issues.

TSH optimal range sits between 0.5-2 mU/L

🗝       fT4 is the storage form of thyroid hormone and has a warming metabolic effect. When someone has lower levels of T4 they’ll feel cold, tired, hungry, grumpy or teary (signs of hypo thyroid issues). It’s not too hard to think of someone that fits that category! Conversely, if you have a lot of heat symptoms, faster heart rate, sore eyes and it’s thyroid related, it may be that T4 is in high levels (signs of hyper thyroid issues).

fT4 optimal range sits between 15-19 pmol/L

🗝       fT3 is the active form of thyroid hormone and mostly is made around the body. It’s influenced quicker than T4 and we need carbs in order to make T3, so In a similar vein to T4, it’s going to translate to feeling cold, hungry, tired, grumpy (signs of hypo thyroid issues) if you’re not eating enough carbs.

fT3 optimal range sits between 4.5-5.6 pmol/L

🗝       Thyroid Antibodies are checked in cases where autoimmune disease is suspected (eg graves or hashimotos disease). You can have a thyroid flare without there being an autoimmune component, but it’s important detail to rule out, or better manage the range they’re in, if antibodies are present.

TPO-Ab optimal range sits <20 IU/mL

TgAb optimal range sits <20 IU/mL

TRAb optimal range sits <1.0 IU/L

Ranges for optimal are tighter than the lab ranges you get back from test results. It’s highly possible to have thyroid symptoms, but be within lab range. This is called a sub-clinical presentation & can be guided by a practitioner who targets optimised care, and how to interpret your results.

Laelia is an Acupuncturist and TCM practitioner who loves to support people in feeling less depleted. You can book in with her here.