Friday, March 1, 2024

What Are The 5 Thyroid Tests

What Is The Thyroid Gland

Thyroid function tests (TFTs) and labs explained in under 7 minutes (ish)

The thyroid gland is a butterfly-shaped endocrine gland that is normally located in the lower front of the neck. The thyroids job is to make thyroid hormones, which are secreted into the blood and then carried to every tissue in the body. Thyroid hormones help the body use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should.

In People Being Treated For Thyroid Disease

A high TSH may be found in people being treated for either hypo- or hyperthyroidism.

With hypothyroidism, a high TSH usually means that the dose of thyroid hormone replacement needs to be increased.

In some cases, however, the dose is okay, but the medication is not being fully absorbed. For example, many foods and medications can affect the absorption of Synthroid in your system. Learning what to avoid while taking this medication is important for it to work properly.

With hyperthyroidism, a high TSH usually means that the treatmentbe it surgery, radioactive iodine, or medicationswas so effective in limiting the production of thyroid hormone that it caused the person to become hypothyroid.

A low TSH often means that a person has an elevated level of thyroid hormones.

What About Thyroid Medications For Subclinical Hypothyroidism

Starting thyroid medication in subclinical hypothyroidism is considered controversial by endocrine groups. Exceptions are made for women who are contemplating pregnancy and for those who have overt hypothyroid symptoms. Guidelines clearly state that in order to avoid pregnancy complications and impaired development of offspring, women with subclinical hypothyroidism need to be treated with thyroid hormones.

At this stage, many patients may also opt to wait and see and may forgo thyroid medications in an effort to do it naturally. I know that I was one of those people, and I waited six months to get on medications after my diagnosis, but knowing what I know now, I am in favor of starting medications for subclinical hypothyroidism.


Korzeniowska and colleagues at the Medical University of Gdansk found that treating children with subclinical hypothyroidism with thyroid hormones, resulted in a decrease of inflammation. This means that the medications gave their thyroids a rest and resulted in a slowing down of the autoimmune attack, manifested by lower levels of thyroid antibodies.

Additionally, in my clinical experience, most patients with subclinical hypothyroidism report feeling much better when they start on thyroid hormones.

Personally, when I was first diagnosed with subclinical hypothyroidism, I didnt want to take medications because I felt like it would be giving up, and that I should figure things out naturally.

Read Also: Diabetes And Thyroid Center Of Ft Worth

What About Those Already On Thyroid Medications

If youre already on thyroid meds, but still have symptoms, it is possible you may need to up your dosage so that your labs fall within the optimal range, to help you feel better.

Please take a look at my article on TSH for a letter that you can take to your physician if he/she is not familiar with the current optimal reference range. As I mentioned earlier, I personally feel best with a TSH a bit under 1 IU/mL, but you may need some trial and error to find your personal best TSH.

Once you establish a dose of medication thats working for you and as long as your symptoms dont change you can test your thyroid hormones every six months.

Controversies Over Optimal Tsh

7 Causes Behind Low Thyroid Function

Many non-modifiable factors influence a person’s TSH levels and dictate what a “normal” value is in an individual. This not only includes variations by a person’s biological sex or age but fluctuations that regularly occur during different seasons of the year.

Some experts argue that the upper limit of a normal TSH should be loweraround 2.5 mU/L. The reasoning behind this is that the vast majority of adults without thyroid disease have a TSH value between 0.45 and 4.12 mU/L. This is especially true in younger females.

Don’t Miss: Different Types Of Thyroid Tests

What To Consider When Searching For An At

In your search for an at-home thyroid test, decide what is most important for your needs. Most tests measure TSH and T4 levels. You may need further tests that measure levels such as T3, T7, TSI, and antibodies. Find out what types of recommendations for additional testing or treatment plans each company offers.

At-home tests can be considered if you have symptoms that cause you to suspect a thyroid disorder. You may also want to test your thyroid levels after implementing lifestyle changes, starting a new medication, or beginning a treatment plan. Its also a good idea to do a home test if you are at risk of developing a thyroid disorder.

At-home thyroid tests offer plenty of advantages and drawbacks to consider.

Best For Support From Thyroid Specialists: Paloma Complete Thyroid Blood Test Kit

This test measures levels of TSH, free T4, free T3, and thyroid peroxidase antibodies , which can be in people with Hashimotos thyroiditis. This company only produces thyroid tests, and its medical team includes endocrinologists, dieticians, and wellness experts.

After a person receives their results, they get ongoing personal guidance from a thyroid specialist. A person also gets treatment recommendations generated by an algorithm that medical professionals supervise, according to Paloma.

The test requires a finger-prick blood sample, and its results are available within a week. A person can choose to add a vitamin D and reverse T3 test to their purchase at checkout.

The company accepts payments from flexible spending accounts and health savings accounts .

The Paloma Complete Thyroid Blood Test Kit costs $99 for non-members and $75 for members. Membership costs $16 a month.

Paloma members can also use their health insurance to pay for appointments with the companys doctors. These cost $42 for people without membership or insurance.

Recommended Reading: Stop The Thyroid Madness Com

Hyperthyroidism In Pregnancy And Postpartum

Hyperthyroid patients should have appropriate specialist consultation ) when contemplating pregnancy or during pregnancy.

In the course of a normal pregnancy, TSH may be low in the first trimester, when human chorionic gonadotropin peaks. Pathological causes of low TSH in pregnancy may include multiple gestation, hyperemesis gravidarum and molar pregnancy14. In this context, a normal fT4 generally excludes hyperthyroidism14, 20. After hCG mediated hyperthyroidism, the most common pathological cause of hyperthyroidism in pregnancy is autoimmune Graves disease. Toxic multinodular goitre and toxic adenoma are less common than autoimmune causes14.

During pregnancy, if TSH is low, repeat the TSH along with fT414 . If TSH is still low and fT4 is high, refer to a specialist in endocrinology or maternal-fetal medicine . If TSH is still low but fT4 is normal, repeat testing in 4 weeks is suggested. If TSH is still low referral to a specialist is recommended.


Because of changes in the modulation of the immune system, there is an increased risk of thyroiditis and new presentation or relapse of Graves disease in the postpartum period14. One study found that hyperthyroidism diagnosed within 3 months of delivery was most often caused by postpartum thyroiditis while hyperthyroidism diagnosed after 6.5 months was caused by Graves disease36.

What Happens If Test Results Indicate A Thyroid Problem

5 Conditions Which Make Your TSH Less Accurate

A person should contact their doctor if they receive a positive test result. The doctor may confirm the result with a blood test in their office or clinic.

Some companies offer follow-up consultations with healthcare professionals, who can answer questions and describe the next steps.

If a person receives a negative result but continues to experience concerning symptoms, they should contact a healthcare professional.

Read Also: Can Thyroid Disease Cause Hives

Hypothyroidism Caused By Decreased Tbg

Low levels of TBG cause free thyroid hormone levels to rise because there are fewer proteins available to bind thyroid hormones. The high circulating levels of T4 and T3 induce cellular resistance to thyroid hormone, much like how cells develop insulin resistance upon continuous exposure to high levels of insulin. This problem means that even though there is plenty of thyroid hormone, cells cant use it. As a result, symptoms of hypothyroidism develop. Patients with this pattern of thyroid dysfunction have normal TSH and T4, high T3, low T3 uptake, and low TBG.

Low TBG can be caused by a high testosterone level. This thyroid pattern often occurs in women with PCOS and insulin resistance because these two conditions lead to elevated testosterone. Insulin sensitivity and blood sugar balance need to be restored to treat this pattern of thyroid dysfunction.

Preparing For The Tests

You dont need to do anything special to prepare for the thyroid function tests. If a healthcare professional has ordered other blood tests to be taken at the same time, you may need to fast for several hours before the test. They will let you know of any special instructions to follow.

Otherwise, you will not need to follow any specific directions before the test.

Read Also: Location Of The Thyroid Gland

Think Twice Before Prescribing Thyroid Hormone

These five patterns of thyroid dysfunction not only fail to show up on lab work but also tend to respond poorly to conventional thyroid hormone replacement. If a patient cant convert T4 to T3, has high or low levels of TBG, or has cells that are resistant to thyroid hormone, then it doesnt matter how much T4 he takes because his body cant properly use it.

Rather than merely prescribing thyroid hormone replacement to patients with hypothyroid symptoms, we need to identify and address the underlying causes specific to each pattern. Selecting appropriate lab tests is crucial for piecing together the factors contributing to a patients thyroid dysfunction.

Learning how to select the right lab tests for thyroid dysfunction requires an investigating mindset and proper training. Like a lot of autoimmune diseases, it can be hard for a practitioner to overlook the prescription pad and try and get to the root cause of the problem. The ADAPT Practitioner Training Program was created to address that gap that a lot of practitioners have when dealing with chronic and complex diseases.

A combination of functional medicine and ancestral health, the ADAPT Practitioner Training Program offers a multi-faceted approach to diagnosing, treating and even reversing some of the modern chronic conditions that plague our society.

What Is Your Thyroid

Normal Tsh Levels : Tsh Secreting Tumors Endocrinology Advisor

The thyroid gland is located at the base of your neck. Its part of the endocrine system and is responsible for regulating hormones throughout your body to help you sleep, give you energy, and help you stay warm.

The main hormones it produces are thyroxine and triiodothyronine , which control how your cells use energy. Your thyroid gland regulates your metabolism through the release of these hormones.

Hypothyroidism occurs when the thyroid doesnt make enough T4, T3, or both. Its the most common thyroid condition, affecting 5% of the population worldwide, with another 5% who have the condition but havent been diagnosed.

In hyperthyroidism, the opposite occurs. The thyroid becomes too active and makes too much of the thyroid hormones.

Testing your thyroid levels at home is convenient and accurate when done correctly, and with the range of home test kits to choose from, you may find one that you like.

Read on to find out what thyroid tests are available and if theyre right for you.

Anyone can get their thyroid checked. However, certain populations can be at higher risk for thyroid disorders, including:

  • people born with a uterus
  • people with autoimmune disorders, including type 1 diabetes
  • people with a history of thyroid disorders
  • people who smoke
  • people with a family history of thyroid disorders

You may want to undergo testing if youre showing any symptoms of hypothyroidism or hyperthyroidism.

Also Check: Over The Counter Thyroid Booster

Thyroid Hormone Level Tests

There are four main thyroid hormones that have been identified: T1, T2, T3, and T4.

T4 and T3 are the two main thyroid hormones. T4 is known as prohormone and is 300 percent less biologically active than T3. T3 is the main biologically active thyroid hormone and gives us beautiful hair, replenishes our energy, and runs our metabolism.

You may have put together that most of the commonly prescribed thyroid medications like Synthroid and levothyroxine, only contain T4 , and thus they need to be converted to the active T3 form in the body.

On paper, the T4 to T3 conversion happens just fine, but in the real world, in real human bodies, we may not always convert T4 to T3.

We can reveal our T4 to T3 ratios and measure the hormone that is available to do its job in the body, by testing our free T4 and free T3 levels.

Free T3 and Free T4 tests measure the levels of active thyroid hormone circulating in the body.

Some clinicians may only test for T4, but T3 is also important to test, as some individuals may not be converting T4 to the active T3 properly. Thus, people may have a normal T4, but a low T3 level.

How Do You Know If You Are Converting Correctly?

Take a look at your free T3 and free T4 levels. Both should be in the optimal ranges noted below, which have been determined by functional medicine guidelines and my clinical experience. If the T4 is optimal, but the T3 is below the optimal range, you know that your body is not making enough T3 hormone from the T4.

How To Advocate For Yourself When You Have Thyroid Problems

Just because you understand what your labs mean doesnt mean youre suddenly a doctor, but you know that! Simply knowing how to read your labs you can help ensure that the right ones are being run, and can help you understand what your thyroid is doing without having to wait for a doctor to explain it to you.

However, when it comes to thyroid labs and adjusting medications in response, this is where you need a practitioner who you can communicate with easily. There are several thyroid medications available and the specific combination youre on, along with dosing changes, can create a nearly endless amount of possibilities.

While lab tests are one way of gauging your thyroid wellness, how you are feeling is another vital component. If, for example, youre hovering near the high end of free T3 but on the low end of free T4, yet you have never felt better, its important to let your doctor know. In cases where your thyroid levels are still normal enough, it might not warrant a dosage change.

If, however, youre smack in the normal range but feeling exhausted or plagued by other thyroid symptoms, it could be that one or more medications youre on are not working. It could also mean that your reverse T3 is high, which is another reason to understand the less common tests that can be run to assess your thyroid status.

Read Also: If Thyroid Levels Are High

Controversies In Care: Treatment Of Pregnant Women With Subclinical Hypothyroidism

Although there is no strong evidence to support routinely measuring TPO antibodies in pregnant women, the American Thyroid Association recommends that treatment may be initiated at lower TSH levels in women known to be TPO antibody positive14. If the TSH value is above 2.5 mU/L but within the reference interval, some practitioners would consider treating if the TPO antibody is positive.

What Does A High Tsh Mean

5 Thyroid lab patterns that Doctors miss

What can happen if the TSH level is too high? If a TSH level is too high, it may be a sign of hypothyroidism. Here are some of the symptoms of hypothyroidism:

There are two main forms of hypothyroidism, or an underactive thyroid:

  • Primary hypothyroidism is when your thyroid is the problem. Theres not another part of your body triggering thyroid dysfunction.
  • Thyroid-stimulating hormone is not a thyroid hormone. TSH is produced in the pituitary gland, but it dramatically affects the thyroid. If you are producing too little TSH, you could suffer from secondary hypothyroidism, which means your thyroid disorder is really a pituitary problem.
  • Another form of secondary hypothyroidism, which some even call tertiary hypothyroidism, occurs when your hypothalamus releases too little thyrotropin. This issue with the hypothalamus can affect the pituitary gland, which in turn affects the thyroid gland.

    What may be causing high TSH? Autoimmune diseases such as Hashimotos, toxin exposure, or even food allergies may be causing high TSH levels, which is due to low thyroid hormone levels and hypothyroidism.

    Recommended Reading: When Should I Have My Thyroid Checked

    When Abnormal Thyroid Function Tests Are Not Due To Thyroid Disease

    While blood tests to measure thyroid hormones and thyroid stimulating hormone are widely available, it is important to remember that no all tests are useful in all circumstances and many factors including medications, supplements, and non-thyroid medical conditions can affect thyroid test results. An endocrinologist can help you make sense of thyroid test results when there is a discrepancy between your results and how you feel. A good first step is often to repeat the test and ensure there are no medications that might interfere with the test results. Below are some common reasons for mismatch between thyroid tests and thyroid disease.

    Non-thyroidal illness Significant illness, such as an infection, cancer, heart failure, or kidney disease, or recent recovery from an illness can cause changes transient changes in the TSH. Fasting or starvation can also cause a low TSH. An endocrinologist can help to interpret changes in thyroid function tests in these circumstances to distinguish non-thyroid illness from true thyroid dysfunction.

    Test interference Biotin, a common supplement for hair and nail growth, interferes with many thyroid function tests and can lead to inaccurate results. Endocrinologists recommend stopping biotin supplements for 3 days before having a blood test for thyroid function.

    What Is Thyroid Hormone

    Thyroid hormone is made by the thyroid gland, a butterfly-shaped endocrine gland normally located in the lower front of the neck. Thyroid hormone is released into the blood where it is carried to all the tissues in the body. It helps the body use energy, stay warm and keeps the brain, heart, muscles, and other organs working as they should.

    Thyroid hormone exists in two main forms: thyroxine and triiodothyronine . T4 is the primary form of thyroid hormone circulating in the blood . To exert its effects, T4 is converted to T3 by the removal of an iodine atom this occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. T3 normally accounts for about 5% of thyroid hormone circulating in the blood.

    Most thyroid hormone in the blood is bound by protein, while only a small fraction is “free” to enter tissues and have a biologic effect. Thyroid tests may measure total or free hormone levels.

    Also Check: Doctors Who Specialize In Thyroid

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