Thyroid Disorder Monitoring: Initial | Quest®

What

This test measures the levels of thyroid stimulating hormone (TSH), thyroxine (T4), and thyroid peroxidase (TPO) antibodies in your blood.

Who

Must be 18+ years of age to purchase.

How

Blood

Where

Find a location near you

Schedule an appointment, then visit one of the Quest Diagnostics Patient Service Centers

About the test

This initial thyroid monitoring panel measures the levels of TSH, T4, and TPO antibodies in your blood. These markers help determine whether your treatment plan is working properly to manage your thyroid disease and can help your provider understand whether your thyroid function is impacted by autoimmune activity. Including TPO antibodies alongside TSH and Free T4 helps provide a more complete picture of thyroid health by distinguishing functional hormone changes from autoimmune activity affecting the thyroid.

This test is intended as a follow-up for those undergoing a treatment option after abnormal Thyroid Function (TSH) Test results.

If you have not been diagnosed with a thyroid disorder but you think you may have a thyroid disorder, consider the Thyroid TSH Function Test first. If you are looking for a more comprehensive hormone workup including everything in this panel plus T3, consider our Women's Hormone Test Panel — Expanded.

No doctor’s visit needed. Buy this blood test for thyroid, visit a nearby Quest location, and get fast results.

Please note: Noticeable changes in your metabolism (weight, temperature, and energy) may be a sign or symptom that there is too much or too little TSH in your blood. If TSH levels are too high or too low, this may indicate your thyroid is overactive (hyperthyroidism) or underactive (hypothyroidism). With this test panel, TSH, T4, and TPO blood levels are measured to help accurately determine whether your initial or adjusted treatment dosage is providing the correct level of support for your recently diagnosed thyroid disorder.

This test panel is intended for patients with a known thyroid concern.

It may be right for you if:

You have a known thyroid condition and need follow-up testing after starting treatment
Your healthcare provider has recommended additional evaluation and assessment for autoimmune involvement beyond initial thyroid screening
You’ve previously completed a Thyroid Function (TSH) Test and you and your healthcare provider need deeper insight as part of ongoing management
You’ve been told you have or may have:
- Subclinical hypothyroidism
- Hashimoto’s disease (autoimmune thyroiditis)
- Painless (silent) thyroiditis
- Postpartum thyroiditis

And want to assess thyroid peroxidase (TPO) antibodies to help understand the likelihood of progression to permanent hypothyroidism

You have a goiter and normal TSH levels and your healthcare provider wants to further evaluate potential autoimmune thyroid involvement

Quest offers multiple tiers of thyroid testing depending on your needs:

Thyroid TSH Function Test, which gives an initial assessment of thyroid function. This is the starting point for most people looking to understand thyroid health and measures TSH with reflex to T4 if results are abnormal
Thyroid Disorder Monitoring — Ongoing, which measures TSH and T4, even without an abnormal TSH result
Thyroid Disorder Monitoring — Initial (this panel), which measures TSH, T4, and TPO to assess potential autoimmune involvement in thyroid issues
Women's Hormone Test Panel — Expanded, which measures TSH, T4, TPO, and T3 as well as additional hormones that are particularly relevant to women’s health

This test measures thyroid-stimulating hormone (TSH), free T4, and thyroid peroxidase antibodies (TPO), three key markers used to evaluate and monitor thyroid function.

About the thyroid

The thyroid is a butterfly-shaped gland in the front of the neck that helps regulate how your body uses energy. It plays a role in many essential processes, including metabolism, heart rate, body temperature, and nervous system function. Thyroid activity is regulated by the pituitary gland, which produces thyroid-stimulating hormone (TSH). TSH signals the thyroid to produce thyroid hormones—primarily T4, which the body converts as needed to T3. When this system is out of balance, it can lead to thyroid disorders that affect many parts of the body. While untreated thyroid disease can increase the risk of complications, most thyroid conditions can be effectively managed with medication and regular monitoring.

TSH helps control how much thyroid hormone your body produces.

High TSH levels may indicate an underactive thyroid (hypothyroidism)
Low TSH levels may indicate an overactive thyroid (hyperthyroidism)

TSH is often the first marker used to assess thyroid function and is commonly tracked over time in people with known thyroid conditions.

T4 is the main hormone produced by the thyroid gland. Free T4 is the portion that is not bound to proteins and is available for the body to use. Measuring Free T4 helps:

Assess how much thyroid hormone is available to tissues
Confirm or clarify abnormal TSH results
Monitor response to thyroid treatment

Thyroid peroxidase (TPO) is an enzyme involved in the production of thyroid hormones. TPO antibodies are produced when the immune system mistakenly targets the thyroid gland. Measuring TPO antibodies helps:

Identify autoimmune-related thyroid conditions
Support evaluation of conditions such as Hashimoto’s disease and certain forms of thyroiditis
Provide additional context when thyroid hormone levels are abnormal or borderline

Elevated TPO antibodies may be present before changes in TSH or T4 are detected and can help predict the risk of worsened thyroid dysfunction. TPO antibody testing is commonly used to support diagnosis and inform long-term monitoring, particularly in individuals with known or suspected autoimmune thyroid disease.

Symptoms of thyroid disorders can be mild, moderate, or severe and often resemble other medical conditions. You may consider getting a thyroid function test if you're experiencing the following symptoms:

Hypothyroidism (underactive thyroid) symptoms can include:

Weight gain
Fatigue
Increased sensitivity to cold
Thinning hair
Enlarged thyroid gland (goiter)
Muscle aches and pains
Joint pain and stiffness
Elevated cholesterol levels
Constipation
Depression
Problems with memory
Slower than normal heart rate
Dry skin
Muscle weakness
Facial puffiness
Hoarseness

Hyperthyroid (overactive thyroid) symptoms can include:

Increased appetite
Irregular heartbeat
Palpitations—a fluttering or pounding heartbeat
Unintentional weight loss
More frequent bowel movements
Anxiety or nervousness
Sweating

Purchaser: You must be 18 years of age or older to purchase a test on questhealth.com.

Patient: This test can be performed on patients between 18 and 100 years old.

Sample collection: This test requires sample collection at a Quest Diagnostics location or through Quest Mobile^TM where available, a convenient location for in-home sample collection*. Collection is not available in AK, AZ, or HI.

*Check your zip code here for service availability, testing may not be available in all locations.

No special preparation is required.

After you provide your specimen, it generally takes few business days to process and release your test results. However, processing times may vary. Your test results will be available in a clear and easy-to-read report. If you have or create a MyQuest® account, you may be able to review your new results there with your other Quest results. If your results differ from expected ranges, you may receive an alert call from an independent healthcare coordinator. Independent healthcare providers are available to discuss questions or concerns you may have regarding your results and may be able to prescribe treatment, if appropriate.

Included with your purchase, you have the ability to discuss your results with an independent healthcare provider who may be able to prescribe hypothyroidism specific treatment, depending on your results.

Compare products

Test For	Thyroid Disorder Monitoring — Initial	Thyroid Disorder Monitoring — Ongoing	Thyroid TSH Function Test	Women's Hormone Test Panel — Expanded
Thyroid-stimulating hormone (TSH), reflex to Free T4
Free T4
Thyroid peroxidase (TPO) antibodies
Free T3
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Estradiol
Testosterone, Total
DHEA, Unconjugated
Prolactin
Progesterone
	$115.00	$72.00 Learn More	$49.00 Learn More	$289.00 Learn More

Thyroid Disorder Monitoring — Initial	Thyroid Disorder Monitoring — Ongoing	Thyroid TSH Function Test	Women's Hormone Test Panel — Expanded
Thyroid-stimulating hormone (TSH), reflex to Free T4
Free T4
Thyroid peroxidase (TPO) antibodies
Free T3
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Estradiol
Testosterone, Total
DHEA, Unconjugated
Prolactin
Progesterone
$115.00	$72.00 Learn More	$49.00 Learn More	$289.00 Learn More

How it works

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Complete your test sample collection during your scheduled appointment.

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1

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No doctor visit required for purchase. If in-home service is available in your area, purchase for an additional $79 fee.

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2

Register your test
& schedule an appointment

After you make a purchase, register your test and Quest Mobile will contact you to schedule an in-home sample collection appointment.

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In-home sample collection

A Quest Mobile phlebotomist will collect your sample and deliver it to Quest Diagnostics.

4

Get fast results

Access results online as soon as they’re available. You will be emailed when they are ready. Discuss your results with an independent healthcare provider at no extra cost. Treatment options may be available.

Please note: Quest Mobile is currently only available for individuals ages 18+.

This guide covers key information about how to get tested for thyroid disorders, including symptoms, available tests, and how to interpret results.

Thyroid disorders can affect men and women of all ages. Getting tested is important, especially for those with a family history, as undiagnosed thyroid disease can contribute to infertility, sexual dysfunction, osteoporosis and heart disease.

FAQs

How common is hypothyroidism?

About 5 percent of Americans who are 12 years old or older have hypothyroidism. Many people who have hypothyroidism are unaware.

Which thyroid disorder is most common, hypothyroidism or hyperthyroidism?

Hypothyroidism is more common.

How often should I have my thyroid function checked?

Currently, there is no evidence to support routine screening of your thyroid function. You may consider checking your thyroid function if you are having symptoms of a thyroid disorder or if you are at high risk for developing a thyroid disease. If you have been diagnosed with a thyroid disorder, you may have your thyroid function checked more frequently. Consult with your healthcare provider to determine a longer-term care plan.

Are there risk factors to be aware of for developing thyroid disease?

Even if you don’t have symptoms, you may consider testing if you have the following risk factors:

Family history of thyroid disease
Women
People over age 50
Have an autoimmune disease such as type 1 diabetes
History of thyroid surgery
Radiation treatment for a past thyroid condition
Recent pregnancy
Taking medication high in iodine

If I have a thyroid condition, how do I obtain treatment for it?

Initial testing for the evaluation of thyroid function should include TSH with reflex to serum T4 when TSH is abnormal. If treatment is started, recommended testing includes TSH and free T4 to be measured 6 weeks after initiation of treatment or if the dose is changed. Once steady state is achieved, annual monitoring of TSH is recommended or as needed if a patient develops new or worsening symptoms.

If treatment is not started, but retesting or monitoring is warranted, it is recommended to test TSH and/or T4.

Testing TPO antibodies is recommended for subclinical hypothyroidism, painless (silent) thyroiditis, Hashimoto disease, or postpartum thyroiditis, to predict the likelihood of progression to permanent overt hypothyroidism. TPO antibody can also be measured in the presence of a goiter in patients with normal TSH. The Thyroid Disorder Monitoring, Initial panel does test for TPO. The Thyroid Disorder Monitoring, Ongoing panel does not test for TPO.

If thyroid (TSH) is abnormal, T4 is also performed on the sample you have already provided.

During the consult, the participant may discuss the results, get educational information, and talk about next steps. If the participant’s results show that he or she has hypothyroidism, the PWN Healthcare Provide may be able to prescribe medication, if appropriate.

Can I use my FSA or HSA funds to purchase tests at questhealth.com?

You may be able to use your FSA or HSA funds to purchase lab tests at questhealth.com. Please review your FSA/HSA plan or check with a tax professional to confirm specific requirements for individual eligibility.

Tests purchased on questhealth.com are only for individuals who intend to pay directly for testing and do not want to submit a claim for reimbursement under their health insurance.