{"id":52827,"date":"2024-11-20T20:07:47","date_gmt":"2024-11-20T20:07:47","guid":{"rendered":"https:\/\/www.easly.nl\/biomarkers\/ft4\/"},"modified":"2024-11-21T20:24:19","modified_gmt":"2024-11-21T20:24:19","slug":"ft4","status":"publish","type":"biomarkers","link":"https:\/\/www.easly.nl\/en\/biomarkers\/ft4\/","title":{"rendered":"fT4"},"content":{"rendered":"\t\t
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fT4 Meaning<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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fT4 stands for free thyroxine 4. Thyroxine 4 is the inactive variant of thyroid hormone. In technical jargon, this is called a precursor. With fT4, the part of Thyroxine 4 that is free (unbound) in the blood is measured. This is because most of thyroid hormone is bound to various proteins. Thyroxine 4 is converted by the body, particularly in the liver, into T3, Trijodothyronine. T3 is the biologically active variant of thyroid hormone.<\/p>\n

To determine thyroid function, it is best to measure the biomarkers TSH and T4.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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fT4 Values in Men and Women: Detailed Explanation<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Here is an overview of fT4 levels in men and women so you can see when your fT4 level is normal, low or high.<\/p>\n

Normal:<\/strong><\/p>\n

An fT4 level between 13.23 and 19.95 pmol\/L is considered normal. This indicates healthy thyroid function in women.<\/p>\n

Low:<\/strong><\/p>\n

An fT4 value below 12.6 pmol\/L is considered abnormal and too low. This may indicate slow thyroid function (hypothyroidism). Interpretation along with the TSH value is recommended. Values between 12.6 and 13.23 pmol\/L are considered \u201celevated,\u201d meaning the fT4 level is at the lower limit of normal and may require further monitoring.<\/p>\n

High:
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An fT4 level above 19.95 pmol\/L falls on the high side of normal. Values between 19.95 and 21 pmol\/L are considered \u201celevated,\u201d indicating that the fT4 level is at the upper limit of normal. If the value exceeds 21 pmol\/L, it is considered abnormal and too high and may indicate an overactive thyroid gland (hyperthyroidism). Further interpretation is then required, in conjunction with the TSH value.<\/p>\n

Invalid:
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A value of 0 pmol\/L is considered invalid, possibly due to insufficient material for the test. A new measurement is recommended.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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fT4 Values in Men et Woman: Detailed Explanation<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Result<\/th>Unit<\/th>Value min-max<\/th>Age<\/th>Gender<\/th>Biomarker interpretation<\/th><\/th>\n<\/tr>\n<\/thead>\n
Not normal<\/span><\/td>pmol\/L<\/td>0 - 12.6<\/td>18 - 20<\/td>Man & Woman<\/td>The fT4 falls outside the normal range and is too low. Interpretation depends on the TSH.<\/td>The cause is usually an underactive thyroid gland (hyperthyroidism).<\/td>\n<\/tr>\n
Take care<\/span><\/td>pmol\/L<\/td>12.6 - 13.23<\/td>18 - 20<\/td>Man & Woman<\/td>The fT4 is still within the normal range, but on the low side.<\/td>Too low a fT4 may indicate a thyroid gland that works too slowly.<\/td>\n<\/tr>\n
Normal<\/span><\/td>pmol\/L<\/td>13.23 - 19.95<\/td>18 - 20<\/td>Man & Woman<\/td>The fT4 is good.<\/td><\/td>\n<\/tr>\n
Take care<\/span><\/td>pmol\/L<\/td>19.95 - 21<\/td>18 - 20<\/td>Man & Woman<\/td>The fT4 is still within the normal range, but on the high side.<\/td>An excessively high fT4 may indicate a thyroid gland that is working too fast.<\/td>\n<\/tr>\n
Not normal<\/span><\/td>pmol\/L<\/td>21 - 100<\/td>18 - 20<\/td>Man & Woman<\/td>The fT4 falls outside the normal range and is too high. Interpretation depends on the TSH.<\/td>The cause is usually a thyroid gland working too fast (hyperthyroidism).<\/td>\n<\/tr>\n
Not normal<\/span><\/td>pmol\/L<\/td>0 - 11.6<\/td>20 - 100<\/td>Man & Woman<\/td>The fT4 falls outside the normal range and is too low. Interpretation depends on the TSH.<\/td>The cause is usually a thyroid gland working too slowly (hyperthyroidism).<\/td>\n<\/tr>\n
Take care<\/span><\/td>pmol\/L<\/td>11.6 - 12.18<\/td>20 - 100<\/td>Man & Woman<\/td>The fT4 is still within the normal range, but on the low side.<\/td>Too low a fT4 may indicate a thyroid gland that works too slowly.<\/td>\n<\/tr>\n
Normal<\/span><\/td>pmol\/L<\/td>12.18 - 20.81<\/td>20 - 100<\/td>Man & Woman<\/td>The fT4 is good.<\/td><\/td>\n<\/tr>\n
Take care<\/span><\/td>pmol\/L<\/td>20.81 - 21.9<\/td>20 - 100<\/td>Man & Woman<\/td>The fT4 is still within the normal range, but on the high side.<\/td>An excessively high fT4 may indicate a thyroid gland that is working too fast.<\/td>\n<\/tr>\n
Not normal<\/span><\/td>pmol\/L<\/td>21.9 - 100<\/td>20 - 100<\/td>Man & Woman<\/td>The fT4 falls outside the normal range and is too high. Interpretation depends on the TSH.<\/td>The cause is usually a thyroid gland working too fast (hyperthyroidism).<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

Find out what normal, low and high fT4 levels mean for your health, the possible consequences of abnormal thyroid function, and how to get your fT4 status measured.<\/p>\n","protected":false},"template":"","biomarkers_category":[1670],"class_list":["post-52827","biomarkers","type-biomarkers","status-publish","hentry","biomarkers_category-hormones"],"acf":[],"yoast_head":"\nfT4 Meaning & Value<\/title>\n<meta name=\"description\" content=\"Find out what normal, low and high fT4 levels mean for your health, the possible consequences of abnormal thyroid function, and how to get your fT4 status measured.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.easly.nl\/en\/biomarkers\/ft4\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"fT4 Meaning & Value\" \/>\n<meta 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