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11 votes
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How does ones TSH tend to vary over the course of a day?

TSH has a quite important circadian rhythm. Most of the original research on it is not freely accessible, as open access wasn't really a thing when these studies were done, in the 80s, but this one ...
YviDe's user avatar
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9 votes

TPO (Thyroid Peroxidase) Antibodies - reference range change

Reference ranges vary by labs. In some assays, 35 IU/mL is still considered the upper limit of normal. The reason for the dramatic difference in reference ranges is the detection limit of the assay ...
Susan's user avatar
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8 votes
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Abnormal thyroid function and obesity - known links?

The relationship between thyroid function and body weight is bidirectional and complex. It is known for decades, if not centuries, that cretinism (only in the end of the 19th century to be ...
jwdietrich's user avatar
6 votes
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Why hormone replacement (e.g. Levothyroxine) for high TSH levels when T3 and T4 levels are normal

The lab parameters you describe (slightly elevated TSH, normal T3/T4) in isolation are an indication of latent hypothyroidism. In general, this is interpreted as a thyroid gland not functioning ...
Narusan's user avatar
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6 votes
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How much T4 increase do you get per mcg of levothyroxine?

First of all, thyroid hormones are actively taken up into cells and accumulate there. Therefore, the apparent volume of distribution for T4 is 10 liters rather than 5 liters (1). Secondly, I would ...
jwdietrich's user avatar
5 votes

Does hyperthyroidism affect serotonin levels?

Thyroid function and serotonin activity are highly linked. Serotonin stimulates hypothalamic TRH (Thyroid Releasing Hormone) production, leading to an increase in TSH (Thyroid Stimulating Hormone) ...
Taylor's user avatar
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4 votes
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Can taking high doses of iodine every day cause psychosis?

Drugs.com mentions that prolonged use of Lugol's solution (potassium iodide + iodine) can cause confusion, caused by potassium. In long-term treatment of Grave's disease (overactive thyroid), 10–400 ...
Jan's user avatar
  • 15.8k
4 votes

What is the quantitative relationship between free T4 and TSH?

The relation between TSH and free T4 is bidirectional and complex [1–4]. TSH stimulates the secretion of T4 from the thyroid gland. Immediately after being released into the bloodstream the vast ...
jwdietrich's user avatar
4 votes

Lab test result meaning

Measurements will always have measurement errors, we distinguish between systematic errors and statistical errors due to noise, or other random effects than on average are zero. Usually the former ...
Count Iblis's user avatar
  • 2,260
3 votes

Alternative sources of iodine for radiation emergency

Here is a potential option that should at least be better than nothing and not particularly risky. Required supplies: Iodized salt High concentration ethanol (>90%) Filter Principle: Iodized salt ...
jpa's user avatar
  • 201
3 votes

Can iodine purification tablets be used to prevent absorption of radioactive iodine (tetraglycine hydroperiodide, potassium iodide)

The answer is yes. I found a couple of studies looking at hydroperiodide function in the thyroid. Both of them were from the same group of authors and from the military, where use of these sorts of ...
bob1's user avatar
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3 votes

How does ones TSH tend to vary over the course of a day?

TSH concentration is subject to both circadian variation (i.e. a rhythm with a period of one day) and ultradian variation (i.e. faster oscillations). This fact is illustrated by the following figure: ...
jwdietrich's user avatar
3 votes

Is eyebrow hair loss common in hyperthyroidism?

The condition that you're asking about is called in the professional terminology: "madarosis" (but see the picture that I attached). As many proffessional books states, it's common in hypothyroidism, ...
Ubiquitous Student's user avatar
3 votes
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Radioactive Iodine for Hyperthyroidism: why avoid contact with others?

The main risk is to children and pregnant women associating with the person receiving I-131 treatment. Since I-131 is excreted in bodily fluids and taken up into the thyroid, those susceptible ...
Graham Chiu's user avatar
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2 votes
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Thyroid Peroxidase (TPO) Ab Test- normal or abmormal

Normal. A result of 9 where the reference range is 0 - 34 indicates that you're within the normal range. For this test, an abnormal result would be a value over 34 because it's not possible to have a ...
Highly Irregular's user avatar
2 votes

Routine exams in patients with hypothyroidism

This also depends on the question if hypothyroidism is subclinical or overt. Recently, the European Thyroid Association has published a guideline on the management of subclinical hypothyroidism. In ...
jwdietrich's user avatar
2 votes
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Synthroid : 30 minutes to 1 hour before meal. What if person waits more than 1 hour

It is directed that way due to the impact of having food in your stomach. It requires an empty stomach for adequate absorption of the drug. Waiting the 30 mins - 1 hour means that there's enough time ...
Robinchwan's user avatar
2 votes

Can you be hyperthyroid even if levels are in Lab range

The personal set-point of thyroid homeostasis may differ between individuals [1, 2]. Multiple studies showed that the intra-individual variation of both TSH and peripheral thyroid hormones is smaller ...
jwdietrich's user avatar
2 votes
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Why might lab test results be normal when thyroid nodules are present and there are symptoms of hyperthyroidism?

This constellation may result from at least five reasons: Hypothesis #0: Both conditions (thyroid nodules and symptoms of hyperthyroidism) are independent. Hyperthyroid symptoms including anxiety, ...
jwdietrich's user avatar
2 votes

Does oral baking soda supplementation improve decreased thyroid function caused by resveratrol?

OK. I'll tackle your question in two parts.... The baking soda part: If you've read the source article cited by you till the end, you will understand that oral sodium bicarbonate, through correction ...
Samuel Cherukuri's user avatar
2 votes
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Can iodine purification tablets be used to prevent absorption of radioactive iodine (tetraglycine hydroperiodide, potassium iodide)

A few thoughts about the dosage: 130 mg KI contain ≈ 780 nmol I (100 mg). One of the linked tablets contains ≈ 94 nmol I (11.9 mg). So, 8 and 1/3 of the water purification tablets have the same amount ...
cbeleites unhappy with SX's user avatar
2 votes

Alternative sources of iodine for radiation emergency

Based on WHO report: Iodine as drinking-water disinfectant page 19, common 10% (often labeled 100 mg/mL) povidone-iodine solution can be used as drinking water disinfectant. The recommended amount for ...
jpa's user avatar
  • 201
1 vote
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What's the rationale behind measuring free T4?

The hypothesis is that the free hormone is the fraction which is available for uptake into the cells and interaction with nuclear receptors. The bound hormone represents actually a circulating storage ...
Farzan's user avatar
  • 131
1 vote

How much Japanase dashi kombu seaweed broth can be consumed daily while not overdosing with iodine and keeping thyroid healthy?

This study from Australia https://www.mja.com.au/journal/2010/193/7/iodine-toxicity-soy-milk-and-seaweed-ingestion-associated-serious-thyroid indicates that iodine toxicity has been documented in ...
Graham Chiu's user avatar
  • 13.2k

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