Series of my posts on the subject, on facebook.com/DrIcaroAlves e instagram.com/DrIcaroAlves.
I've been studying a lot about thyroid and I'm sharing with you some advanced information on the subject: useful for you (or someone you know) and still not widely covered, as far as I know.
1. Before you go any further, learn the basics about the thyroid or you may not understand what comes next: icaro.med.br/TIREOID
2. The TSH released by your pituitary gland (gland in your brain) both stimulates the production of T4 by the thyroid and the conversion of this T4 into T3 in various places in the body; in other words: too little TSH is not good either - too much is bad for you.
3. The liver is one of the places where enzymes most transform T4 into T3 (the active form of thyroid hormone), which is why when it is inflamed, intoxicated or overloaded, a patient can easily show symptoms of hypothyroidism; therefore, when this is the case, substances that help the liver can help the effect of thyroid hormones, such as silymarin (from milk thistle), acetylcysteine, boldo, etc.
4. Inflamed intestines impair the conversion of T4 into T3, both by producing inflammatory mediators and by disturbing the intestinal bacterial flora (which, in part, also converts); and guess what else inflames the intestines? Poor diet (icaro.med.br/Food) and bad lifestyle habits (https://icaro.med.br/15habitos/)
5. Remember: there's a lot more to know about the thyroid at icaro.med.br/Thyroid - you need to check it out!
Of course: don't self-medicate; before putting what I've said into practice, the ideal thing is for you to submit this quality knowledge to the analysis of your trusted health professional, ok?]
PART 2:
5. T3 (icaro.med.br/T3) and not the T4 that your thyroid produces or that you take in the form of Levothyroxine (Puran, Levoid, Synthroid, Euthyrox, etc.). All T4 has to “lose” an iodine molecule in the tissues where it will act, so that it can become T3 and only then effectively act and increase local metabolism; in other words, just taking the “thyroid medicine” doesn't guarantee that you will “automatically” have your hypothyroidism compensated, since there are many cases in which the patient doesn't properly convert T4 into T3 (due to bad lifestyle habits, lack of nutrients, poisoning, inflammation, hormonal deficiencies, etc).
6. Having TSH levels within laboratory parameters does not guarantee that your hypothyroidism is “compensated”! TSH is the brain's order (via a gland called the pituitary gland) for the thyroid to produce T4 (and a little T3 itself) and the more T4 the thyroid produces, the more this T4 tells the brain that there is “enough” T4 in the body and that TSH release can therefore decrease. The problem is that if this “enough” T4 isn't turning into “enough” T3, TSH will stay “within the acceptable range” and your doctor will tell you that “everything is fine”, but in reality it probably isn't!
7. Therefore, as a doctor, I'd like to say that I don't think it's enough to use TSH and T4 tests alone to say that someone has an “OK thyroid” or sufficient thyroid hormones in their body. I suggest that the most complete and appropriate assessment should follow these parameters: https://icaro.med.br/exames-para-avaliacao-da-tireoide-o-que-voce-precisa-saber/
PART 3:
8. Those who lead a low-activity life (few activities, little physical exercise, low level of brain demand, etc.) naturally have a reduction in T4 production and/or in the activation of T4 into T3, as a way of keeping the metabolism low in proportion to the level of activity of each person. In general, a functional thyroid disorder (and often an adrenal disorder) should be suspected when, at a certain point in life, someone needs to respond more “intensely” to a potentially stressful situation but is unable to do so, which includes both physical and mental, emotional demands, fighting infections, etc.
9. The mineral selenium is very important for the activation of key enzymes for the conversion of T4 into T3, which is why the thyroid is the tissue in the body where this mineral is proportionally most present. As it is also important for the proper activity of the immune system, its deficiency has been implicated as one of the causal or aggravating factors in autoimmune diseases that attack the thyroid, such as Hashimoto's Thyroiditis. Various foods are good sources of selenium, but Brazil nuts are the best known source in our country (of course, provided that they ideally come from good soil or their nutrient content will be reduced).
10. When the hormone cortisol is too high (for example, in “somewhat longer-lasting” situations of high stress), this reduces the conversion of T4 into T3 and can lead to symptoms of hypothyroidism. It's worth remembering here that if stress goes on for too long, many people stop producing enough cortisol and can develop chronic fatigue (https://icaro.med.br/fadiga/), a situation in which the thyroid tends to be overworked in an attempt to compensate for the adrenals (which produce cortisol and various other hormones) and ends up exhausting itself over time.
PART 4:
Thousands of people have accessed my material on thyroid (https://icaro.med.br/?s=Tireoide), especially icaro.med.br/hypothyroidism/ e https://icaro.med.br/tireoide/, videos on https://www.youtube.com/dricaroalves, for which I am very grateful in my work!
And the most common question I've received in recent months is: “Doctor, what tests are needed to assess the Thyroid”?
Answer: Your doctor, who is competent and up-to-date, is the best person to answer this, assessing your individual needs - not least because your case may require more or less detailed examinations.
However, in general, what I ask my patients as soon as they come to see me are:
- TSH, Free T4, Free T3, Reverse T3, Thyroglobulin and Ultrasound (US=Ultrasound=Ecography) (I explain details about these in the links above: I strongly recommend that you access, read, watch!)
- Ideally, however, for a first consultation, I also ask for Antibodies (e.g. Anti-TPO, Anti-Thyroglobulin, Anti-TSH), Total T4, Total T3 and Doppler ultrasound (gives more details, in case of nodules or cysts) - if the patient can pay for these and/or their health insurance covers them, in order to make their assessment more complete.
It is worth noting, however:
- Except in situations where the patient has no functioning thyroid (either completely removed or completely neutralized by treatments such as radioactive iodine), this noble gland responds VERY WELL to improving lifestyle habits, which is fundamental to restoring its health: https://icaro.med.br/15habitos/
- Proper investigation of any organ, including glands, first requires a detailed consultation, where the patient's complaints are listened to in an attentive and detailed manner and complemented by examinations. Performing tests without relating their results to detailed clinical data often leads to errors in diagnosis and treatment.
- The thyroid doesn't work on its own and often in order to recover/optimize its functioning the patient will need to supply it with nutrients that are often lacking, such as Selenium, Iron, Zinc, L-tyrosine, etc - nutritional adequacy and supplementation, when necessary, ideally require competent professional advice and monitoring.
- In other cases, in addition to the above corrections, the patient often needs to optimize the functioning of other glands (for example, when the adrenals “go bad” the thyroid can more easily be driven to exhaustion) and even replace other hormones, since they affect the production of thyroid hormones (and can suppress or hyperstimulate it): for example, adequate levels of GH and Melatonin are necessary for adequate production of T4 (Thyroxine), testosterone and progesterone deficiencies (and high levels of leptin, commonly increased when there is excess body fat) usually reduce the conversion of T4 into T3 by various tissues/organs in the body.
Got it?
PART 5:
On thyroid, hypothyroidism and related subjects, lots of information for you here:
icaro.med.br/hormoniosdatiroide/
icaro.med.br/exames-para-avaliacao-da-tireoide-what-you-need-to-know/
For example:
- Is all hypothyroidism Hashimoto's?
- Can it be cured?
- Do nodules and cysts necessarily mean that the gland isn't producing hormones properly?
- Is iodine necessary or harmful?
- Does food affect anything?
- Is it related to other glands and hormones in the body?
- Who needs T3 in addition to T4?
- Does everyone need an ultrasound? And biopsy?
- Who can monitor and treat?
Do lifestyle habits affect the thyroid? Go here and check out these and many other answers - I've updated the link with yesterday's Q&A video!
Português do Brasil 
English 