The doctor ordered a blood test to diagnose the thyroid gland. But not every doctor explains how to do it right. And the patient may have the most unexpected questions about the rules for donating blood to the thyroid hormones. Therefore, we will consider typical rules for such a study, and each reader will be able to ask his personal question on this topic in a comment.
1. A list of blood counts that should be ordered in the laboratory.
The minimum set is three indicators: TSH (thyroid stimulating hormone), T4-free (thyroxine) and T3-free (triiodothyronine).
It is erroneous to determine only TSH, or TSH and T4-fr., or TSH with total T4 and T3.
If you are performing a blood test for the first time, then it is better to evaluate all the main indicators: TSH, T3fr., T4fr., T4total., T3total., AT-TPO, AT-TG.
If you mean the presence of node (-s) in the thyroid gland, then order an assessment of calcitonin. With thyrotoxicosis - AT-rTSH.
Recent scientific studies have confirmed the mandatory assessment of all three blood counts. Read about this in the article:
Distortion of diagnosis and treatment for hypothyroidism. New scientific evidence!
The story from life.
A couple of times it was that I myself donated blood in the laboratories. For some reason, young women immediately appeared behind me, drawing up documents for the analysis of blood TSH and T4fr. with the administrator of the laboratory.
I tried to prompt. He presented himself as a thyroidologist (after the thyroid gland) and reported that it was necessary to determine, along with TSH and T4fr, also T3-free - the main thyroid hormone (as he told them). But they only smiled sweetly, as if they were told compliment. Nothing in their order has changed.
2. When is it best to donate Blood for Analysis?
Traditionally, it is proposed to perform in the morning on an empty stomach. But in the case of thyroid hormones and TSH, you can donate blood to the laboratory at any time of the day.
Of course, there are daily fluctuations in TSH and thyroid hormones, but they have little effect on the values of hormonal parameters and antibodies.
Is it better to donate blood at the same time? Yes, but not necessary.
3. Does one need to stop taking the drug before donating blood for analysis?
With hypothyroidism, patients take hormonal drugs and / or potassium iodide. With hyperthyroidism - thyreostatics. In these two cases there is no need to worry.
Usually, doctors recommend determining hormones in the blood in the morning on an empty stomach before taking the drug. Then take the drug and after 40 minutes breakfast. This is ideal, but completely optional.
The fact is that drugs act mainly cumulatively. Therefore, if you forgot to use a medicine on some day, you should not take a double dose the next day!
Also, one should not give up hormone or thyreostatic drugs (Eutirox, L-thyroxine, Tyrosol, Propitsil, etc.) for a long period (1-4 months) to obtain real data. A competent doctor will be able to orient to some extent if you indicate the dose taken and the duration of use.
Piece of advice. Label the dose and name of the drug on the blood test form, as well as the duration of this particular dose. Save the blood test forms.
So, stop taking the drug before donating blood is not necessary.
4. Does the reliability of a blood test for thyroid hormones and TSH depend on the day of the menstrual cycle?
Usually, there are no significant effects of the period of the menstrual cycle on the reliability of the assessment of thyroid blood parameters. You can donate blood any day of the cycle. But better between menstrual days.
5. Does the administration of antibiotics, vitamins, NSAIDs and contraceptives affect the result of a blood test "on the thyroid gland"?
Many medications have almost no effect on the results of a blood test for thyroid hormones and TSH. But there are tools that can slightly "distort" the picture. In addition to the hormones of the thyroid gland and thyreostatics, drugs containing iodine can also influence. Such funds, for example, include cordarone (amiodarone).
To everyone who is determined to independently understand the results of a blood test, we suggest paying attention to the book of Dr. A.V. Ushakov, head doctor of the Thyroid Clinic (Moscow):
If your region does not have summer weather (cold and rains) ... for diseases of the thyroid gland, and not only...
How to help your thyroid gland and the body as a whole, if the summer is gone and only teases with rare sunny days. How to maintain thyroid health? What to do?
This summer of 2019 is very unusual. In some regions there is hot weather, but in others this summer they forgot about heat and sunny days. Even on the Black Sea coast (in particular in Bulgaria), coolness was not typical of mid-August.