How to interpret your TSH result, common questions, and next steps to take

Thyroid-stimulating hormone (TSH) is a hormone produced by the pituitary gland that stimulates the production of hormones from the thyroid that are essential to many bodily functions such as metabolism, brain development, bone health, muscle control, heart rate, and body temperature.

Thyroid dysfunction is under-diagnosed with some population studies indicating that up to 10% of Americans may have thyroid dysfunction. TSH is considered the most sensitive marker for thyroid screening. When the thyroid is taxed or under-active (such as in hypothyroidism), TSH levels increase in an effort to further stimulate thyroid function and the production of thyroid hormones. Even a borderline-underactive thyroid is associated with certain health concerns, such as fatigue, unexplained weight gain, infertility, and mood swings.

Hyperthyroidism is often diagnosed when the TSH is very low and there is a relatively rapid onset of symptoms of an overactive thyroid: irritability, diarrhea, heart palpitations, heat sensitivity, and insomnia.

Additional tests may be recommended if TSH levels are out of range to give a more definitive diagnosis of thyroid disease or imbalance. The treatment and diagnosis must be undertaken with a medical doctor or other primary health care provider.

How to read your results

Your latest TSH result is located on the chart on the left side of the “TSH” tab on your “my Test Results” page.

Next to that is a chart displaying each of your TSH results plotted over time.

NOTE: The images below are for demonstration only and do not reflect your personal results.

Below this you will find a table your latest and past TSH results. The latest results will be at the top.

What is a normal TSH level?

The normal TSH range depends on a person’s age and pregnancy status, with levels tending to be higher as a person gets older and lower during pregnancy. According to the American Thyroid Association, doctors generally consider levels between 0.4 and 4.0 µU/mL to be within the normal range with levels between 0.0 and 0.4 µU/mL indicating hyperthyroidism, levels between 4.0 and 10.0 µU/mL indicating mild hypothyroidism, and levels 10 µU/mL or higher indicating hypothyroidism. However, some experts consider normal levels to be between 0.5 and 2.0-2.5 µU/mL.

What can you do to support healthy thyroid function?

Nutrients such as iodine, selenium, zinc, B-vitamins, vitamin D, vitamin A and amino acids are needed for optimal thyroid health and function. Other body systems important for thyroid health must also be supported, including the gut, adrenals, and the brain; if they aren’t working optimally the thyroid will also be negatively impacted.

Learn more here.

What are the TSH levels of other participants?

Among the 229 participants who had tested their TSH levels at the time of our last analysis, the average level was 1.5 µU/mL. As you can see from the chart below, 86% of these participants had levels in the normal range, 5% had levels in the range indicating possible hyperthyroidism, 7% had levels in the range indicating possible mild hypothyroidism, and 2% had levels indicating possible hypothyroidism.


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