The hormonal balance of this axis works on the principle of feedback:<\/p>\n
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When T3 and T4 levels decrease<\/strong>, the pituitary gland produces more TSH;<\/p>\n<\/li>\n
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when there are too many of them, TSH decreases.<\/p>\n<\/li>\n<\/ul>\n
Thanks to this mechanism TSH analysis allows us to suspect thyroid pathology even with normal T3 and T4 levels<\/strong>.<\/p>\n
When should you take a TSH test?<\/h2>\n
The analysis is indicated in the following cases:<\/p>\n
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symptoms of hypothyroidism: fatigue, cold sensitivity, dry skin, depression;<\/p>\n<\/li>\n
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symptoms of hyperthyroidism: anxiety, sweating, tachycardia, weight loss;<\/p>\n<\/li>\n
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infertility, menstrual irregularities, decreased libido;<\/p>\n<\/li>\n
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enlargement of the thyroid gland (goiter);<\/p>\n<\/li>\n
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control of hormone replacement therapy (levothyroxine);<\/p>\n<\/li>\n
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planning or monitoring pregnancy;<\/p>\n<\/li>\n
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newborns and children with signs of developmental delay.<\/p>\n<\/li>\n<\/ul>\n
Normal TSH Values: Age and Clinical Guidelines<\/h2>\n
TSH norms may vary slightly depending on the laboratory, but they are roughly as follows:<\/p>\n
\n\n\n\n
\n \nPatient category<\/th>\n TSH norm (mIU\/L)<\/th>\n<\/tr>\n<\/thead>\n \n Adults<\/td>\n 0.4 \u2013 4.0<\/td>\n<\/tr>\n \n Optimum when planning<\/td>\n 0.4 \u2013 2.5<\/td>\n<\/tr>\n \n Pregnant women (1st trimester)<\/td>\n 0.1 \u2013 2.5<\/td>\n<\/tr>\n \n Pregnant women (2nd\u20133rd trimesters)<\/td>\n 0.2 \u2013 3.0<\/td>\n<\/tr>\n \n Children under 12 months.<\/td>\n 0.5 \u2013 7.0<\/td>\n<\/tr>\n \n Children under 5 years old<\/td>\n 0.7 \u2013 6.0<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n \n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n
In the practice of endocrinologists, the upper limit is often lowered to 2.5\u20133.0 mIU\/L, especially in patients planning pregnancy.<\/p>\n<\/blockquote>\n
How to properly prepare for the analysis?<\/h2>\n
For accurate results, follow these recommendations:<\/p>\n
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Donate blood in the morning (until 10:00)<\/strong> on an empty stomach.<\/p>\n<\/li>\n
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Do not take thyroid medication.<\/strong> on the day of delivery (as agreed with the doctor).<\/p>\n<\/li>\n
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By day before analysis<\/strong> avoid physical and emotional overload.<\/p>\n<\/li>\n
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Notify the doctor about the appointment iodine-containing or hormonal drugs<\/strong>.<\/p>\n<\/li>\n<\/ul>\n
![\"illustration](\"https:\/\/medilab.km.ua\/wp-content\/uploads\/2025\/06\/krupnym-planom-ruka-s-percatkoi-derzasei-pipetku.jpg\")
<\/p>\nHow to interpret the results?<\/h2>\n
The results should be considered in context other indicators (T3, T4, anti-TPO)<\/strong>, and not in isolation. The general directions of interpretation are as follows:<\/p>\n
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Elevated TSH + decreased T4<\/strong> \u2192 primary hypothyroidism;<\/p>\n<\/li>\n
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Elevated TSH + normal T4<\/strong> \u2192 subclinical hypothyroidism;<\/p>\n<\/li>\n
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Decreased TSH + increased T4\/T3<\/strong> \u2192 hyperthyroidism;<\/p>\n<\/li>\n
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Reduced TSH + reduced T4<\/strong> \u2192 secondary hypothyroidism (pituitary gland pathology).<\/p>\n<\/li>\n<\/ul>\n
It is also worth considering temporary states:<\/p>\n
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TSH may increase after acute viral infections<\/strong>, operations or in patients with goiter without functional impairment<\/strong>.<\/p>\n<\/li>\n
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A decrease in TSH is possible with: stress, starvation<\/strong>, some medications (glucocorticoids, dopamine, thyroid hormones).<\/p>\n<\/li>\n<\/ul>\n
Why is it important to monitor TSH during pregnancy?<\/h2>\n
Thyroid insufficiency in pregnant women is one of the factors delays in mental and motor development of the fetus<\/strong>. That is why:<\/p>\n
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TSH levels in a pregnant woman should be lower than in a normal adult<\/strong>;<\/p>\n<\/li>\n
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With hypothyroidism, a pregnant woman definitely needs hormone dose adjustments<\/strong>;<\/p>\n<\/li>\n
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control is carried out every 4\u20136 weeks<\/strong>.<\/p>\n<\/li>\n<\/ul>\n
What to do after receiving the results?<\/h2>\n
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Do not prescribe treatment yourself - TSH is only assessed together with other hormones<\/strong>.<\/p>\n<\/li>\n
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Contact us endocrinologist or therapist<\/strong>, especially if you have accompanying symptoms.<\/p>\n<\/li>\n
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If you are already on levothyroxine therapy, the result will help adjust the dose<\/strong>.<\/p>\n<\/li>\n<\/ul>\n
A blood test for TSH is a simple, accessible, but strategically important test<\/strong>, which allows you to detect even hidden thyroid disorders in time and prevent them from becoming chronic.<\/p>","protected":false},"excerpt":{"rendered":"
What is TSH and why is it clinically important? Thyroid-stimulating hormone (TSH) is a hormone that,<\/p>","protected":false},"author":627,"featured_media":9920,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,233],"tags":[],"class_list":["post-9919","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zahvoryuvannya-ta-symptomy","category-rozshyfrovka-analiziv-ta-pidgotovka"],"_links":{"self":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/posts\/9919","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/users\/627"}],"replies":[{"embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/comments?post=9919"}],"version-history":[{"count":0,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/posts\/9919\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/media\/9920"}],"wp:attachment":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/media?parent=9919"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/categories?post=9919"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/tags?post=9919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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