Thyroid-stimulating hormone (TSH) is an essential hormone that controls the activity of the thyroid gland. It sends the signal to the thyroid gland to produce thyroid hormone when the level of thyroid hormone in the blood decreases. Now, the question arises that what value of TSH will be considered as normal in the human body. Well, the level of TSH varies in individuals depending upon the gender, age, and stage of life, that is, the optimum range may differ in pregnant and non-pregnant females of the same age. This article will help you explore the normal range of TSH in individuals on the basis of their age, gender and stage of life cycle. 

Did you know that signs of extreme fatigue, sensitivity to cold, weight gain, puffiness around the face, constipation, etc. that we take for granted could be signs of thyroid diseases? Getting tested for the TSH levels isn’t just a necessity but ideal for your peace of mind. The last thing you want is to get diagnosed with a disease that was likely preventable with an early diagnosis.

 

What is the optimum range of TSH in the human body?

The typical range of TSH lies between 0.4 mU/L to 4.0 mU/L. According to studies, approximately 30% of patients with TSH above 3.0 mU/L suffer from autoimmune thyroid disease. The optimum levels of TSH for different groups of people are described below.

The TSH normal range for adult age groups (males):

According to the study conducted in 2013, the reference range of TSH in adults is:

• The normal level of TSH in males between 18 - 50 years, lies between 0.5 - 4.1 mU/L. TSH level less than 0.5 mU/L, indicates a low TSH value, and a TSH level of more than 4.1 mU/L, indicates a high TSH value.
• The normal level of TSH in males between 51 - 70 years, lies between 0.5 - 4.5 mU/L. TSH level less than 0.5 mU/L, indicates a low TSH value, and a TSH level of more than 4.5 mU/L, indicates a high TSH value.
• The normal level of TSH in males between 71 - 90 years, lies between 0.4 - 5.2 mU/L. TSH level less than 0.4 mU/L, indicates a low TSH value and, a TSH level of more than 5.2 mU/L, indicates a high TSH value.

The TSH normal range for adult age groups (females):

As per the studies, females are at a greater risk of developing thyroid condition than males. This is because of the hormonal fluctuation that occur in females during different stages of their life, that is, menstruation, pregnancy and menopause. The reference range of TSH for non-pregnant females is:

• The normal level of TSH in females between 18 - 29 years, lies between 0.4 - 2.34 mU/L. TSH level less than 0.4 mU/L, indicates a low TSH value and a TSH level of more than 2.34 mU/L, indicates a high TSH value.
• The normal level of TSH in females between 30 - 49 years, lies between 0.4 - 4.0 mU/L. TSH level less than 0.4 mU/L, indicates a low TSH value and a TSH level of more than 4.0 mU/L, indicates a high TSH value.
• The normal level of TSH in females between 50 - 79 years, lies between 0.46 - 4.68 mU/L. TSH level less than 0.46 mU/L, indicates a low TSH value and a TSH level of more than 4.68 mU/L, indicates a high TSH value.

The TSH normal range in children:

The reference range of TSH greatly differs as the child grows. The TSH range for children is:

• Children who are 0-4 days old, have TSH levels between 1.6 - 24.3 mU/L. TSH level less than 1.6 mU/L, indicates a low TSH value, and a TSH level of more than 24.3 mU/L, indicates a high TSH value.
• Children who are 2-20 weeks old have TSH levels between 0.58 - 5.57 mU/L. TSH level less than 0.58 mU/L, indicates low TSH value and a TSH level of more than 5.57 mU/L, indicates high TSH value.
• Children who are 20 weeks to 18 years old have TSH levels in a range of 0.55 - 5.31 mU/L. TSH level less than 0.55 mU/L, indicates low TSH value and a TSH level of more than 5.31 mU/L, indicates high TSH value.

The TSH normal range in pregnant women:

The normal range of TSH in pregnancy varies from one trimester to another. The TSH range considered optimum during pregnancy is:

• In the first trimester, the TSH levels range from 0.6 - 3.4 mU/L. TSH level less than 0.6 mU/L, indicates a low TSH value, and a TSH level of more than 3.4 mU/L, indicates a high TSH value.
• In the second trimester, the TSH levels range from 0.37 - 3.6 mU/L. TSH level less than 0.37 mU/L, indicates a low TSH value and a TSH level of more than 3.6 mU/L, indicates a high TSH value.
• In the third trimester, the TSH levels range from 0.38 - 4.0 mU/L. TSH level less than 0.38 mU/L, indicates a low TSH value and a TSH level of more than 4.0 mU/L, indicates a high TSH value.

What do abnormal levels of TSH indicate?

The levels of TSH state a lot about your health. The level of TSH is inversely related to the level of thyroid hormone in the blood. The abnormal level of TSH indicates:

• Abnormally high levels of TSH indicate the underactivity of the thyroid hormone. This condition is known as hypothyroidism.
• Abnormally low levels of TSH indicate the overactivity of the thyroid hormone. This condition is known as hyperthyroidism.

Takeaway:

Thyroid-related issues are one of the most common endocrine disorders prevalent in recent times. The knowledge of the optimum range of TSH in your body according to your gender, age and the stage of your life can help you better analyze your health conditions and take proper precautions and treatment before the condition worsens.

Frequently Asked Questions (FAQs)

1. How can I know my TSH level?

You can easily know about your TSH level by simply getting a blood test done. The test can be booked easily at Redcliffe labs by making an appointment through call or booking the test online. The phlebotomist will come to your place and collect your sample for the testing.

2. How much will the TSH test cost?

The TSH test at Redcliffe labs costs approximately Rs 199/- only.

3. What if my TSH level in above the reference range?

If the level of TSH in your body is greater than the reference range then you may have one of the following:

• Cretinism
• Primary hypothyroidism 
• TSH-dependent hyperthyroidism
• Thyroid hormone resistance

4. What if my TSH level is below the reference range?

• Hyperthyroidism 
• TSH deficiency
• Effect of some medications like dopamine agonists and glucocorticoids.