Thyroid Test Analyzer: Understanding High and Low TSH, T3, T4, and More (2024)

This thyroid test analyzer will help you understand your TSH, T3, T4, and other thyroid function test results. Select a test and enter your lab value to learn more.

“This tool is aimed to help you interpret your thyroid function test in order to clarify your diagnosis or track the progression of treatment. Please make sure you discuss with your doctor your concerns or questions.” – Ana Maria Kausel, MD.

Helpful Resources

Thyroid disease is common yet often misunderstood or overlooked. If your thyroid test results are outside of the optimal range—or if you’ve been diagnosed with hyperthyroidism, hypothyroidism, Graves’ disease, Hashimoto’s thyroiditis, or another thyroid-related condition—Verywell offers free resources to help you better understand and manage your condition. We want to help ensure you have productive and empowering discussions with your physicians.

Explore the following articles, tools, downloads, and communities to learn more:

Frequently Asked Questions

What information do I need in order to get my thyroid test analysis?

All you need is the name of the test and the test value, as listed on your thyroid test results report that you receive from your doctor. You’ll need to provide both pieces of information to receive an analysis.

All test values should be numerical values—no need to add units, we’ll add those for you!

Which thyroid tests can be analyzed?

Our tool can analyze results from these common thyroid function tests:

  • Thyroid stimulating hormone (TSH)
  • Free thyroxine (Free T4)
  • Free triiodothyronine (Free T3)
  • Radioactive iodine uptake (RAIU) at 6 and 24 hours
  • TRH stimulation test
  • Thyroglobulin antibody
  • Thyroid peroxidase antibodies (TPO)
  • Thyroid Stimulating Immunoglobulins (TSI)
  • Thyrotropin receptor antibodies (TRAb)
  • Reverse T3

It will also analyze results from these thyroid tests that have been largely replaced but are still used in some practices:

  • Total thyroxine (T4)
  • Total triiodothyronine (T3)
  • Free thyroxin index (FTI)
  • T3 resin uptake (T3RU)
  • Thyroid binding globulin (TBG), measured by electrophoresis and radioimmunoassay

You can analyze one test at a time. Remember, however, that many of these tests are related and the various thyroid hormones interact with each other and are affected by multiple factors. Your doctor is the best person to analyze your results as a whole—this tool is meant for informational purposes only.

Download this guide for a full overview of each thyroid function test, its optimal range, and what the results mean.

Download: Understanding the Various Thyroid Function Tests

Where can I find my thyroid test results or lab report?

In most cases, your test results will be ready a few days after your bloodwork or imaging test. You can obtain a copy from your doctor’s office, either at a visit or by calling in.

Your doctor will have the results even if the tests were performed outside of their office. They will likely call or schedule an appointment to review them with you. You can use this tool before or after your discussion to learn more about the different tests and results.

Some labs and offices also offer online patient portals where you can view your results without having to call in. Select the name of the test, as indicated on your report, and enter it into the analyzer, along with your listed numerical value, to receive an analysis.

Note that different laboratories may have different reference ranges for these tests. The reference ranges used in the analyzer are meant to represent typical ranges. If the ranges differ, you should refer to the specific ones provided by the laboratory in which the test was performed.

What information will I receive from the tool?

Once you enter your information, the thyroid function test analyzer will tell you if your result is low, optimal, or high and what that might mean. You’ll also learn a little bit about the test, why it’s done, and what it measures.

Patients with thyroid cancer, pregnancy or pituitary disorders must seek a specialist's care.

How were the results analyzed?

Your results analysis was completed by a board-certified physician. Optimal range values and interpretations are in line with leading thyroid authorities (although they sometimes slightly vary across laboratories).

Remember, however, that this analysis is for informational purposes only. You should use it as a starting point or to further understand what you have already discussed with your doctor. It is not a replacement for a professional medical visit.

Thyroid conditions and hormones are complicated and test results may be affected by multiple factors. Your doctor is the best person to take a holistic look at you, your medical history, and the relationships between your different thyroid hormones. They can provide you with the most customized, accurate interpretation and next steps to follow.

Who else can see my lab results or personal analysis?

We take online privacy very seriously, especially when it comes to individual and personalized health information. We do not track which lab tests you analyze and we do not store any lab values you enter. You are the only one who can see your analysis. Also, you will not be able to return to your results, so if you would like to save them it is best to print them.

Please see our Privacy Policy for more information.

Can this tool diagnose me with a thyroid condition?

This tool does not provide medical advice or diagnosis. It is intended for informational purposes only and is not a substitute for professional medical consultations, diagnosis, or treatment.

What should I do with the analysis?

You should use the analysis to empower yourself and learn more about your results, but not to diagnose yourself with a thyroid-related condition, such as hyperthyroidism, hypothyroidism, Graves’ disease, or Hashimoto’s thyroiditis. Proper diagnosis and treatment require a holistic look at your previous medical history, symptoms, lifestyle, and more. Your doctor is the best person to do this.

You can use this information to inspire questions or use it as a starting point for a conversation with your doctor at your next appointment. Asking the right questions can help you know what to expect.

Also, consider bringing along a doctor discussion guide for even more guidance—it lists common vocabulary terms your doctor may use and important questions about symptoms, causes, diagnosis, treatment, and living well with thyroid disease.

Download: Thyroid Disease Doctor Discussion Guide

Thyroid Test Analyzer: Understanding High and Low TSH, T3, T4, and More (2024)

FAQs

What does it mean when T3 and T4 are high and TSH low? ›

A low level of TSH and high levels of T3 and/or T4 usually means you have an overactive thyroid. Doctors may refer to these measurements as "free" T3 and T4 (FT3 and FT4). What's considered normal varies depending on things such as your age and the exact testing technique used by the laboratory.

How to interpret thyroid test results? ›

TSH and FT4

If the TSH level is high and the FT4 result is low this suggests an underactive thyroid (hypothyroidism) that requires treatment. If the TSH level is low and the FT4 result is high this suggests an overactive thyroid (hyperthyroidism) that requires treatment.

What if only TSH is high and T3 and T4 are normal? ›

Subclinical hypothyroidism represents a state with increased values of thyroid stimulating hormone (TSH) and normal values of thyroxine (T4) and triiodothyronine (T3). The disorder is asymptomatic, and the diagnosis is made based on the results of laboratory findings when the level of TSH reaches values above 4.0 mU/l.

What is an alarming TSH level? ›

What levels of TSH are concerning? TSH levels below 0.4mU/L indicate hyperthyroidism, while levels of about 4.0mU/L and above indicate hypothyroidism. The further the result from these levels, the more severe the result is.

What are optimal thyroid levels? ›

It's often the most sensitive indicator that a thyroid problem is present. The normal range of TSH levels in adults is between 0.4 to 4.0 mIU/L (milli-international units per liter). Some research suggests that this range should actually be more like 0.45 to 2.5 mIU/L.

Which is more important, T3, T4 or TSH? ›

However, TSH is always the best first test because it is more reliable than plasma T3/T4 levels, which tend to fluctuate. In primary hypothyroidism, TSH levels are elevated due to the loss of negative inhibition on the anterior pituitary. In contrast, in primary hyperthyroidism, TSH levels go down.

What can throw off a thyroid test? ›

What can affect thyroid test results?
  • Certain medications and supplements.
  • The time between the last time you took your thyroid medication and when a provider draws your blood. ...
  • Whether you ate before your test (only a factor with thyroid scans).
  • Stress, including the effects on a non-thyroidal illness.

How do I read my TSH report? ›

The TSH test measures the level of thyroid-stimulating hormone in your blood. The TSH has a normal test range between 0.4 and 4.0 milli-international units of hormone per liter of blood (mIU/L). If you show signs of hypothyroidism and have a TSH reading above 4.5 mIU/L, you're at risk of progressing to hypothyroidism.

Which is more important, FT3 or FT4? ›

When hypothyroidism is suspected, the most reliable test appears to be FT4 (together with TSH), because FT3 may still be normal in patients with subclinical or mild thyroid failure.

What mimics hypothyroidism? ›

  • Angioedema.
  • Bronchitis.
  • Bulimia Nervosa.
  • Chronic Obstructive Pulmonary Disease.
  • Congestive Heart Failure.
  • Depression.
  • Menopause.
  • Preeclampsia.

What thyroid level requires medication? ›

If you have no symptoms and only slightly high TSH levels, you usually won't need treatment. Many doctors only recommend treatment if the TSH levels are very high (over 10 mU/L). Other factors may also play a role in the decision, such as how high your overall risk of cardiovascular disease is.

How to confirm secondary hypothyroidism? ›

Diagnose primary or secondary hypothyroidism by testing serum TSH and T4. In primary hypothyroidism, TSH is elevated and T4 is low; in secondary hypothyroidism, both TSH and T4 are low.

What is a good TSH level for age? ›

Understanding TSH Levels and How They Vary
Age rangeNormalHigh
18–30 years0.5–4.1 mU/L> 4.1 mU/L
31–50 years0.5–4.1 mU/L> 4.1 mU/L
51–70 years0.5–4.5 mU/L> 4.5 mU/L
71–90 years0.4–5.2 mU/L> 5.2 mU/L
Feb 25, 2024

What level of TSH is critical? ›

Risk of heart disease related to damage to blood vessels was higher when TSH level increased over 10 mIU/L. The risk of stroke was slightly less when TSH level was between 3-3.5 mIU/L and 4-10 mIU/L. Risk of death was higher when TSH level was lower than 0.1 mIU/L or especially above 10 mIU/L.

Does high TSH cause weight gain? ›

According to one study conducted by researchers at the National Heart, Lung, and Blood Institute's Framington Heart Study, small increases in TSH levels led women to gain an average of 5 pounds over the study's three-and-a-half-year follow-up period.

Should I worry if my TSH is low? ›

A low TSH and a low FT4 may indicate pituitary disease. Detection of central hypothyroidism should prompt your doctor to check for problems in other pituitary hormones, an underlying cause, and you may need imaging tests to look at the pituitary gland. Central hypothyroidism is treated with thyroid hormone replacement.

Does low TSH cause weight gain? ›

Since the BMR in the patient with hypothyroidism (see Hypothyroidism brochure) is decreased, an underactive thyroid is generally associated with some weight gain. The weight gain is often greater in those individuals with more severe hypothyroidism.

What are the warning signs of hyperthyroidism? ›

Symptoms
  • Losing weight without trying.
  • Fast heartbeat, a condition called tachycardia.
  • Irregular heartbeat, also called arrhythmia.
  • Pounding of the heart, sometimes called heart palpitations.
  • Increased hunger.
  • Nervousness, anxiety and irritability.
  • Tremor, usually a small trembling in the hands and fingers.
  • Sweating.
Nov 30, 2022

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