No difference was found between serum TSH concentrations of male (n = 636; 52.6%) and female (n = 573; 47.4%) children and adolescents (p = 0.689) of all age groups. Therefore, both sexes were combined for the calculation of percentiles. Log transformation was done before analysis because of the significant right-tailed skewed distribution of the TSH values. The 97.5th percentile was significantly higher in the age group of 0 – 1 month compared to all other age groups.

In these situations, free T4 (FT4) is low or high respectively; when this occurs, the diagnosis of an overt thyroid illness is very likely, and the child will need to be referred to a pediatric endocrinologist. It is important to evaluate TSH levels in the context of age, since TSH normal ranges are higher in infancy when compared to older children.

July 21, 2025 - Normal levels of free T4 vary based on your age. In general, normal ranges of free T4 for healthy people include: Children up to 5 years old: 0.8 – 2.8 nanograms per deciliter (ng/dL).

In the rare syndromes of thyroid hormone resistance, serum TSH levels are elevated in the presence of normal-to-high serum total T4 concentration. Serum TSH levels are often mildly abnormal (≤ 7 mIU/L) in children and adolescents who are morbidly obese (>20 lb overweight).

September 9, 2018 - In the neonatal period, mild hypothyroidism can be defined by the presence of a TSH value between 6 and 20 mIU/L and normal FT4 levels. After the neonatal period, SH can be defined mild if TSH ranges between 4.5 and 10 mIU/L. The management ...

August 9, 2023 - Some children and adolescents are more at risk of developing overt hypothyroidism. 8-year, Ali has an elevated TSH and normal free T4. His weight and height are both normal. He is asymptomatic and does not have a goitre. His thyroid ultrasound is normal, and thyroid antibodies are negative.

May 14, 2020 - An isolated elevation of free T4 with a normal TSH level would be a rare combination in pediatrics. It could be the result of interfering substances such as biotin23 or heterophile antibody.

June 8, 2020 - Estrogens, such as in birth control pills, cause high levels of total T4 and T3 by increasing the thyroid binding protein. This typically does not change how thyroid hormone works in the body. In these situations, it is better to ask for TSH with free T4 (rather than the total T4). Biotin, a commonly taken over-the-counter supplement, can cause several thyroid function tests to look abnormal, when they are in fact normal.

An overweight child may have a higher TSH level (like hyperthyroidism). A child with hypothyroidism may be mildly overweight, but not significantly overweight or obese. Hypothyroidism slows the metabolism and activity levels, but the child isn’t very hungry. How much fat someone has greatly affects how much thyroid-stimulating hormone (TSH) they make. The TSH level is above normal in a child who is overweight, but that’s not due to an underactive thyroid, and hormone replacement won’t help.

Serum TSH levels were within the normal reference intervals for all children (testing performed at CNMC; data not presented). All samples were kept at −80°C until analysis. 3,3′,5-Triido-l-thyronine (T3) and l-thyroxine (T4) were purchased from Sigma (St. Louis, MO). Deuterium-labeled T4 (T4-d5): T4-[tyrosine 2H5] was obtained from IsoSciences (King of Prussia, PA) and served as the internal standard. High ...

This question comes up a lot online: "What are the optimal reference ranges for thyroid hormone labs in children?" I hope this post serves to help parents and physicians understand optimal reference...

Babies with newborn screen specimens ... and transient CH. High TSH and low free T4 concentrations on serum testing confirm the diagnosis of primary hypothyroidism....

November 10, 2019 - In very rare cases, congenital hypothyroidism can be temporary. In these cases, a child will have normal T4 and TSH levels throughout the first 3 years of life without any changes in the dose of thyroid medication.

There were 54 patients (59%) whose TSH remained elevated in the 5–10 range, and only 11 patients had TSH increase to >10 mU/ml; in all cases it was between 10.5–15 mU/L. Free T4 levels remained normal in all patients. No lab test done at baseline was predictive of either normalization or ...

September 19, 2023 - The typical range of TSH values for children aged 6 to 10 years is 0.8 mU/L to 6.0 mU/L. The diagnosis of hyperthyroidism is indicated by low levels of TSH, which is a consequence of excessive thyroid hormone production.7 A repeat TSH test is ...

In neonates, if venous TSH levels are persistently above 20 mIU/L with normal fT4 levels, initiation of L–T4 treatment is advisable. However, if TSH levels are between 6 and 20 mIU/L with normal fT4 levels, the decision to start treatment should be individualized [16,17]. In children with ...

Subclinical hypothyroidism does not typically cause any · symptoms and does not appear to have any significant · health effects. It may be discovered because of the · presence of a goiter, increased weight, or a strong family · history of thyroid disease.

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These two labs are called TSH and free T4 (thyroxine).