What Your TSH Cannot Tell You About Your Thyroid

thyroid TSH levels

Thyroid TSH levels are the subject of a big controversy. A TSH test is the standard blood test that is recommended in most countries by regulatory medical boards to screen for thyroid disease, make diagnosis and to monitor thyroid replacement therapy.

While the medical community and doctors rely on this test in treating thyroid disorders the effectiveness of this approach is highly questionable because many patients continue to not feel well.

Today I am going over the common thyroid imbalances that cannot be diagnosed and treated by using the TSH test alone. Go through the list and see what applies to you because it could be the answer to why you still have persistent hypothyroid symptoms that just don’t go away.

What is TSH

Thyroid-stimulating hormone or TSH is produced by the pituitary gland and it stimulates the thyroid gland to produce thyroxine (T4) and triiodothyronine (T3). The hypothalamus is a gland that releases TRH (thyrotropin-releasing-hormone) to trigger the secretion of TSH.

TRH (thyrotropin-releasing-hormone) => Thyroid Stimulating Hormone (TSH) => T4 and T3 thyroid hormones

The amount of thyroid hormones produced by the thyroid gland is regulated via the thyroid pituitary feedback loop:

– when you become hypothyroid and the T4 levels drop, the TSH levels increase

– when you become hyperthyroid and T4 levels increase, the TSH falls

Thyroid pituitary feedback loop

However, when it comes to thyroid disease there are

3 Major Problems With Using TSH Test

1. No clear agreement between regulatory boards about thyroid screening

TSH is a commonly used marker in conventional medicine to diagnose hypothyroidism and hyperthyroidism. In fact, according to the American Thyroid Association’s “Guidelines for the Treatment of Hypothyroidism” (2014), TSH is the only test recommended to use for thyroid disease screening.

However, there is no clear agreement between medical boards when to start with routine screening of thyroid disease and who should be screened:

  • The American Thyroid Association (ATA) recommends beginning TSH screening in all adults at age 35, with repeat tests every 5 years.
  • The American Academy of Clinical Endocrinology (AACE) recommends routine TSH screening in older patients, with no specified age.
  • The US Preventive Services Task Force (USPSTF) continues to recommend against routine screening for thyroid disease among non-pregnant women and asymptomatic adults and recommends targeted TSH screening only for patients with certain risk factors instead.

Absence of clear recommendations when and who to screen for thyroid disease created a situation in our society when thyroid disease often remains undiagnosed, misdiagnosed and mistreated. As a result millions of people are affected and don’t even know that they have a thyroid disease.

2. TSH normal reference range is too wide to ensure absence of hypothyroid symptoms

Most doctors run the TSH test alone not only for thyroid screening but also to monitor hypothyroidism treatment, effectiveness of hormone replacement therapy and to adjust your medication dosage.

The problem is that being told that “Your TSH test is normal” doesn’t really have any meaning until you know your exact thyroid TSH levels and ensure that your doctor follows the new TSH normal reference range.

In 2003 The American Association of Clinical Endocrinologists (AACE) reviewed and recommended new TSH normal rages as between 0.3 and 3.0. This means that you are considered hyperthyroid when your TSH is lower than 0.3 and you are hypothyroid when your TSH is higher than 3.0.

Despite these changes many doctors and most laboratories in the United States still use the outdated 0.5 to 5.0 range as their normal reference range for the TSH test. When a lab sends test results to doctors they don’t mark TSH between 3.0 and 5.0 as abnormal and diagnosis of hypothyroidism can be missed.

Furthermore, normal reference ranges are not the same as optimal. Ideally you want to have a TSH at the level of a healthy person or optimal. Studies show that a TSH in the lower end of the normal reference range between 1.0 and 1.5 is the normal level for people who don’t have a thyroid disease.

If your TSH is in the normal reference range it doesn’t mean that it is optimal and you produce sufficient amount of thyroid hormones. Your symptoms can still be due to hypothyroidism or Hashimoto’s disease if your thyroid TSH levels are not optimized.

3. Reliance on TSH alone for thyroid screening leaves room for a missed diagnosis

Most doctors still use TSH as the gold standard of thyroid screening and testing. However, the TSH test alone doesn’t give the whole picture and cannot be used to diagnose many types of thyroid disease.

Let’s look into the cases when relying on the TSH test alone is not sufficient to make a diagnosis or even misleading.

5 Common Cases When TSH Test Alone Is NOT Enough

1. TSH test is not indicative for autoimmune thyroid disease like Hashimoto’s thyroiditis and is useless for early diagnosis and prevention

The progression from Hashimoto’s to hypothyroidism occurs gradually and it can take up to 10 years until hypothyroidism can be diagnosed using the TSH test. Many researches agree that euthyroid Hashimoto’s and high thyroid antibodies (TPO and Tg) precede the hypothyroidism diagnosis by 2-7 years and can be useful early indicators of predisposition to develop hypothyroidism later in life.

However, new research shows that cytological studies can be a better more reliable early indicator of Hashimoto’s disease. Based on the ultrasound and FNA biopsy researches of the Thyroid Multidisciplinary Clinic at the University of Wisconsin came to the conclusion that about 50% of their newly diagnosed patients that came for the evaluation of their thyroid health issues, already had Hashimoto’s thyroiditis even without their thyroid antibodies elevated and TSH in the normal reference range.

Their findings indicate that inflammatory infiltration in the thyroid gland indicative of Hashimoto’s thyroiditis occurs first and only then thyroid antibodies can become elevated. This means that

Another useful approach to early diagnosis and the possible slow down of autoimmune thyroid disease is the evaluation of the immune system. In fact, there are 3 autoimmune disease tests you can do to catch imbalances of your immune system early.

It is important to look for early indicators of autoimmune thyroid diseases because it may help to slow down its progression and gives higher chances for the disease remission or a complete reversal without developing hypothyroidism and the need to manage it with thyroid medication.

However, the TSH test is NOT suitable for these purposes and screening for thyroid disease using TSH test alone will inevitably result in missing Hashimoto’s diagnosis.

2. TSH test doesn’t point to the cause of hypothyroidism

It is a well-known fact that up to 90% of hypothyroidism in industrialized countries is due to autoimmune Hashimoto’s thyroiditis. Major cause of hypothyroidism in the third world countries is iodine deficiency, however Hashimoto’s is starting to become more common.

The problem is that the TSH test cannot be used for early diagnosis and prevention of hypothyroidism caused by either Hashimoto’s as I mentioned above or iodine deficiency. In a matter of fact, the TSH test alone cannot point to the cause of your thyroid dysfunction at all.

TSH test results can just tell you if you are hyper- or hypothyroid according to the medical guidelines but it doesn’t indicate what environmental factors or trigger events are involved and should be considered when choosing a treatment.

The truth is that a proper treatment of hypothyroidism is not possible without finding and addressing the cause of thyroid dysfunction.

3. TSH test alone is not adequate to prevent pregnancy complications

It is important to note that only recently trimester-specific reference ranges for thyroid TSH levels were proposed by ATA (2011) for women during pregnancy. If the iodine intake is optimal the following normal reference ranges are recommended for:

  • first trimester, 0.1–2.5 mIU/L;
  • second trimester, 0.2–3.0 mIU/L;
  • third trimester, 0.3–3.0 mIU/L

TSH in pregnancy

This has important implications when it comes to hypothyroidism diagnosis and treatment in pregnancy, however new research studies show that it may not be enough to achieve a healthy pregnancy and ensure a healthy baby.

There are new studies indicating that there 3 hidden dangers that cannot be evaluated using TSH test alone during and after pregnancy:

– A potential negative impact of subclinical hypothyroidism and subclinical hyperthyroidism on the health of mother, fetus and future intellect of the unborn child

– An association between miscarriage and preterm delivery in women with thyroid TSH levels in the normal reference range but positive for TPO and/or Tg antibodies

– The prevalence and long-term impact of postpartum thyroiditis

As a result, the TSH test alone is not enough to prevent pregnancy complications and ensure healthy fetus development.

4. TSH test cannot help to detect thyroid nodules as well as presence and recurrence of thyroid cancer

It is important to know that thyroid function tests cannot be used as indicators of thyroid cancer. People who have thyroid cancer and nodules often don’t have any symptoms and their TSH is in a normal reference range.

As a result having normal thyroid TSH levels doesn’t guarantee that you don’t have a thyroid disease.

TSH Test Fails

5. TSH test can be misleading in certain circumstances

In addition, there are some other clinical situations when relying on the thyroid TSH levels may be misleading:

– Abnormal function of hypothalamus or pituitary gland including TSH-producing pituitary tumors.

– Transition during treatment periods. For example, TSH readings are unreliable and changing during the early stage of hypothyroidism treatment with thyroid drugs because it takes between 6 and 12 weeks for the pituitary to re-balance in response to thyroid medication and new thyroid hormone levels.

– Temporary episodes of thyroiditis and postpartum thyroiditis when conflicting values of TSH and free T4 may also be encountered.

– Certain drugs such as dopamine and glucocorticoids that influence pituitary TSH secretion or thyroid hormone binding to plasma proteins, may also cause contradictory TSH values.

As you can see, there are many external factors and clinical situations when the TSH test alone doesn’t reflect the whole picture on what is happening to your thyroid and additional thyroid testing is needed.

The Easiest Way To Test Your Thyroid 

If your doctor doesn’t know about, refuses to check your thyroid or order any other tests besides standard thyroid tests like TSH or TSH plus total T4, the easiest way to have your blood work done and get the answers is to order your Thyroid Home Test Kit (use discount code DISEASE25 to get 25% OFF) online from a private lab.

The best part is you don’t need doctor’s referral or medical insurance and don’t even need to go to the lab (which is important for many people in times of COVID-19). The thyroid test kit will be mailed to you and you mail it back to the lab and access your test results right after they are ready.

All lab tests are easy to order, have FREE shipping (USA, UK, Ireland and Europe, just choose your country on the order page), with results sent directly to you within days. All from the safety of your home.

No going to the lab required.

So, instead of going from one doctor to another, hope (or even fight) for the right tests to be ordered and waste years of your life suffering, you can actually shortcut this exhausting and frustrating process by ordering thyroid tests yourself and get your results explanation by a qualified nurse or lab’s doctor.

This step alone often helps to discover much faster what you don’t know about your thyroid yet and what factors potentially limit your recovery from hypothyroidism and Hashimoto’s disease. Most importantly it can help to shift your thyroid treatment focus to where it should be in order to become hypothyroid and autoimmune symptom-free.

If it’s something you need and are willing to do, the lab I recommend for thyroid and autoimmune testing is offering 25% off on all lab testing. You just need to use the discount code DISEASE25 at the check out.

Remember that if your current thyroid treatment doesn’t work consider starting with a proper thyroid testing and learn why your thyroid is out of balance before you do anything else.

Get Your Thyroid Test Kit HERE

thyroid test kit

There are many other tests that can be ordered online and sent to the lab for testing. This includes hormones, women’s health, diabetes, cortisol and many others. This lab offers FREE shipping (USA, UK, Ireland and Europe). You can check out other tests here

Don’t forget to use the discount code: DISEASE25 to get 25% off

P.S. Thyroid problems are so much more than thyroid TSH levels. This is the reason why so many people remain undiagnosed, untreated and undertreated for years, how your thyroid treatment can fail and why you are still suffering from hypothyroid symptoms regardless of your “normal” thyroid TSH levels.

The longer you continue to just manage your hypothyroid and Hashimoto’s symptoms, the worse they become and the longer it will take to get better.

The truth is that so many things that we are led to believe are “right” for our thyroid are actually some of the worst things we could have been doing and can only cause more damage. Learn about research-based treatment and experience the major transformation that occurs during this program to your thyroid health.

Best Hypothyrodism Treatment

P.P.S. Do you like what you read? Get my FREE Hypothyroidism Diet Guide and FREE Hypothyroidism Seminar: The Right And Wrong Ways To Heal and get your FREE probiotic, protein, skin cream and pain-relief cream here


1 Hashimoto thyroiditis is more frequent than expected when diagnosed by cytology which uncovers a pre-clinical state. Thyroid Res. 2010 Dec 20;3(1):11.
2 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and Postpartum

About Marina Gutner, PhD

Marina Gutner, PhD, researcher, medical writer, thyroid blogger, founder and Admin of Outsmart Disease who writes about life-changing treatments for hypothyroidism, Hashimoto's thyroiditis and autoimmune disease and how to balance hormones in women