English 4 MIN READ 54 VIEWS November 20, 2023

What are the Normal Thyroid Levels?

Written By HealthKart
Medically Reviewed By Dr. Aarti Nehra

Your doctor may recommend a thyroid function test to determine if you have a thyroid disorder. Now, the thyroid is a butterfly-shaped gland located at the lower part of the neck. It is a part of the endocrine system, which releases hormones into the blood that impact your body’s metabolism, heart function, brain development and bone health. Any imbalance in the hormone level may cause health implications. The good news is most thyroid health conditions are treatable.

But, thyroid test results can be confusing. In this blog, we’ll talk about normal thyroid levels, necessary tests, and what to do when diagnosed with a thyroid disorder.

What is Thyroid Hormone?

Thyroid hormones are secreted by the thyroid gland to help your body in regulating metabolism.

The thyroid gland produces following hormones:

  • Thyroxine (T4): This hormone is produced by the thyroid gland. It is considered inactive because specific organs in your body transform it into T3 so that it can impact your cells and metabolism.
  • Triiodothyronine (T3): This hormone is an active form of T4 and it regulates your metabolism and other vital functions.
  • Calcitonin: This hormone helps regulate calcium and phosphate levels in your blood so that you have healthy bones.

Role of TSH (Thyroid-Stimulating Hormone)

The pituitary in your brain releases TSH to signal the thyroid gland to make hormones. The amount of TSH that the pituitary sends to the blood depends on the thyroid hormone levels present in the body. Once T4 levels in the blood exceed normal levels, the pituitary stops making TSH. 

Healthcare providers check the levels of TSH and thyroid hormones in thyroid blood tests to determine any disorder. If your results are within the TSH normal range of 0.5 to 5.0 mIU/L, you most likely don’t have any thyroid conditions.

What’s the TSH normal range by age? TSH levels tend to be more elevated in people who are over the age of 80. Most older people with high levels don’t have any thyroid disorders. Pregnant women have low TSH levels in the first trimester.

Did You Know?
The TSH (thyroid-stimulating hormone) is the first test a doctor examines when checking for thyroid levels. Any imbalance in its levels signals that your thyroid is not functioning well. 

Symptoms of Thyroid Issue

High thyroid levels or low levels of thyroid hormones cause noticeable symptoms. Since thyroid hormones help regulate your metabolism, too many hormones can make it faster and too few can slow it. These imbalances show signs such as:

  • Unexplained weight loss or gain
  • Fast or slow heart rate
  • Intolerance to heat or cold
  • Dry skin
  • Irregular menstrual cycles
  • Constipation or frequent bowel movements

If you have these symptoms, you should contact your healthcare provider for a blood test to check your levels.

What’s Included in a Thyroid Panel Test?

Several blood tests measure how well your thyroid gland is functioning. These tests include:

  • TSH: This test is usually the first one that the doctors recommend. The pituitary gland in our body produces TSH, which then signals the thyroid gland to produce T3 and T4.
  • T3: This test checks the triiodothyronine level in your blood. T3 hormone is one of the two main hormones the thyroid gland produces.
  • T4: This test checks the level of thyroxine in your blood. T4 hormone is the other primary hormone produced by the thyroid gland.
  • Antibodies: This test determines types of autoimmune thyroid conditions.
  • Thyroglobulin: This test diagnoses thyroiditis (inflammation) and monitors thyroid cancer treatment.

These tests can help diagnose various illnesses, such as:

  • Hyperthyroidism (Overactive thyroid)
  • Hypothyroidism (underactive thyroid)
  • Thyroiditis (thyroid inflammation)
  • Graves’ disease (an autoimmune disorder)
  • Hashimoto’s disease (an autoimmune disorder)
  • Thyroid nodules
  • Goitre (enlarged thyroid gland)
  • Thyroid cancer

Normal Thyroid Hormone Levels

  • High TSH indicates low thyroid hormones (hypothyroidism), and low TSH signals high hormone levels (hyperthyroidism). 
  • High T4 signifies hyperthyroidism; low T4 suggests hypothyroidism, with exceptions like pregnancy, illness, or medication effects on T4 levels. 

These are the normal ranges to understand thyroid hormone levels better.

Normal TSH Levels0.5 to 5.0 mIU/L. It may vary in situations such as pregnancy, thyroid cancer and pituitary disease.
FT4 (Free Thyroxine) 0.7 to 1.9 ng/dL. It may vary due to medications, thyroid cancer and pituitary disease.
Total T4 (Thyroxine) 5.0 to 12.0 μg/dL
Total T3 (Triiodothyronine) 80-220 ng/dL
Free T3 (Triiodothyronine)Assays are often unreliable and not routinely used for assessment
Expert Tip
To maintain normal thyroid hormone levels naturally, it’s essential to exercise regularly, get sufficient sleep, eat a healthy diet and manage stress levels.


In conclusion, we now know that thyroid disease is a common medical condition that can be managed with the appropriate treatment regimen. It’s vital to maintain your thyroid hormones and TSH levels. Any imbalance can lead to complications. Consult a healthcare provider if you think you have symptoms such as unexplained weight loss or gain, dry skin, and excessive fatigue. Regular tests and early treatment will help you maintain your overall health.

Leave a Reply

Your email address will not be published. Required fields are marked *

Read these next