TSH is the most used thyroid lab test. However, it is not very specific. So why doctors use it? Because most doctors oversimplify the examination of thyroid function.
They rely only on TSH value and not investigate patient's symptoms adequately. It's not the best strategy, because sometimes a patient is symptomatic even with normal TSH and yet a doctor does not dig deeper and refuses to have a proper look at the symptoms.
So how can we investigate it properly?
We can use secondary tests to check the cause of the symptoms.
Secondary tests that come into play are:
Adrenal Stress Index
Hair mineral analysis test
Hormone panel (for both male and female)
With the above tests, We can help patients to prevent the development of many thyroid disorders and autoimmune thyroid conditions.
Unfortunately, these additional tests are not part of the regular annual tests.
But what about TSH? What are the reference values and optimal values?
The reference values are 0.5-5.0 uU/ml, the optimal one is 0.5-1.0 uU/ml.
Why are the optimal values lower than 1.0 uU/ml?
Well, You will rarely see a healthy person having a value higher than 1.0 uU/ml.
Usually, when a person has a value of TSH higher than 1 and certainly higher than 2, it means that it's an early sign of underlying thyroid dysfunction and potential hypothyroidism.
This is a problem because most of the doctors will wait until TSH is high enough (around 6-7) to start the treatment, instead of focusing on prevention, while the TSH is slightly increased and not in the optimal range.
Don't get us wrong, We're not saying that every person with TSH 1.5 has to be immediately treated.
We believe though that every person with TSH higher than 1 and 2 has to make additional tests to improve the optimal values and prevent disease later in life.
We're also not saying that every person with TSH<1 is healthy because we know that in thyroid diseases we should concentrate not only on TSH but also on patient's symptoms (as stated before).
This means that there are cases of patients with perfect TSH (i.e. lower than 1), but still experience symptoms of hypothyroidism.
Cases of such patients involve:
1)High Insulin and Leptin Resistance:
Leptin and insulin resistance causes an increase of reverse T3 (a metabolically inactive form of T3). It makes TSH values diagnostically incomplete, because even with perfect optimal TSH <1, a patient does not have enough of active T3 form. It results in very poor metabolism, problems with weight loss, chronic tiredness and many others.
2) Partial Thyroidectomy:
Patients after partial thyroidectomy can have increased levels of reverse T3, which leads to hypothyroid symptoms. In this scenario, the best way is to check reverse T3 and address the change of medications to improve active T3 levels.
3) High inflammatory states:
High inflammatory states may increase the conversion of T4 to reverse T3. The same story, even with perfect TSH levels, patients may be still experiencing the symptoms of hypothyroidism.
4) Hashimoto's thyroiditis:
The patients with normal reference TSH levels by elevated antibodies to Thyroid peroxidase or Thyroglobulin.
5) The low T3 syndrome, also known as the euthyroid sick syndrome or nonthyroidal illness syndrome (NTIS):
This syndrome characterises fall in serum T3 levels that may be accompanied by a drop in serum T4 levels. Results in an increase of reverse T3 (inactive T3 form). Causes: high inflammatory state in the body, chronic disease, autoimmune disease, high stress for the organism
To sum up:
As You can see, TSH value can help You to understand if Your thyroid is working optimally (TSH<2, ideally <1) or if You may have an initial state thyroid disease ( TSH >2).
If TSH is >2, the additional tests should be done to asses Your health status.
These tests are very important to prevent or treat the initial and later thyroid diseases.
Unfortunately, most of the additional health tests are not offered by a public diagnostic medical model.
That's why You should find a doctor who will help You with analysis of these tests.
What's more, sometimes TSH testing is not enough, as we've seen in 1-5 patients' cases.
That's why You should not only ask Your doctor to analyse additional tests that check Your overall health status but also do additional labs such as for reverse T3.
What's the point of these additional labs?
Well, It will help us understand the cause of Your symptoms. For example, You can have a perfect TSH, but due to insulin resistance, You can have increased levels of reverse T3 and thus suffer from hypothyroidism symptoms.
This means that the first step would be to treat Your insulin resistance to improve active T3 levels and decrease reverse T3 levels.
This is very important because the early treatment of this condition can avoid a lot of pain later in Your life when TSH increases and doctor will make a definite diagnosis.
Remember, it's always better to monitor and prevent rather than treat the disease.