Your Cart is Empty

February 13, 2023 11 min read

Hypothyroidism is a complex condition that can cause a variety of unpleasant symptoms, but what if your TSH test results come back normal? If you're feeling fatigued, gaining weight, and have cold hands and feet—it can be incredibly frustrating to receive results indicating that everything is "fine." So why do you experience hypothyroid symptoms if your TSH test result is normal? In this article, we'll explore some potential reasons and solutions.

The basics of the thyroid function

Thyroid gland

The thyroid gland is a small, butterfly-shaped organ located in the neck that produces two types of hormones – T3 (triiodothyronine) and T4 (thyroxine). These hormones are important for regulating metabolic processes and cell growth in the body. Thyroid hormones play an essential role in helping us stay healthy and function properly.

T4 is the inactive form of thyroid hormone, while T3 is its active form. When released into circulation, T4 undergoes enzymatic conversion to become T3. But not all T4 becomes T3. A small amount of it converts to reverse T3 (rT3), which is the inactive form of T3 and goes through other changes in your body. The amount of the hormones produced depends on how much stimulation it receives from another hormone called thyroid-stimulating hormone (TSH).

Pituitary gland

The pituitary gland is a little gland around the size of a pea, yet it has a huge impact on overall health and vitality. It is sometimes called the "master gland" because it regulates the production of hormones by virtually every other gland in the endocrine system.

One of the hormones produced and released by the pituitary gland is the thyroid-stimulating hormone (TSH). This hormone plays an important role in regulating thyroid hormone production. When the thyroid hormone in your bloodstream is low, your pituitary gland will release more TSH to trigger the thyroid to produce more hormones. When you have too much thyroid hormone, your level of TSH will be lower.


Hypothyroidism is one of the most common thyroid diseases. Also called underactive thyroid gland, this condition occurs when the thyroid produces and releases an insufficient amount of hormone. Without enough thyroid hormones, you'll experience physical and mental problems. Some of the most common hypothyroid symptoms are dry skin, fatigue, anxiety, and irregular menstrual period.

The most common cause of hypothyroidism is a thyroid disease called Hashimoto's thyroiditis. This is an autoimmune condition when your immune system mistakenly attacks your thyroid gland. As a result, your thyroid gland won't be able to produce a normal amount of hormone. Other common causes include radioactive iodine (RAI) and surgical removal of the thyroid gland (thyroidectomy).

To diagnose hypothyroidism, your doctor will perform thyroid function tests.

Why do I experience symptoms of hypothyroidism if my TSH test is normal?

How do doctors test your thyroid function?

Many different blood tests can be performed to evaluate thyroid function. "Blood test" means drawing and sending blood to a lab. Doctors or commercial labs may perform this. The following are the most common tests to determine the health of your thyroid:

1. Thyroid-stimulating hormone (TSH ) Test 

The TSH blood test is the first test your doctors will likely use to assess thyroid function. Since TSH stimulates the production of the thyroid hormone, its level can show you if your thyroid is making enough hormones. High TSH levels usually indicate that your thyroid is underactive and produce an insufficient amount of hormone.

It's important to keep in mind that the TSH test might not always give the full story about your thyroid. If your TSH test results are not normal, your doctor might suggest additional testing to get a clearer picture of what's going on.

2. Free T4 Test

T4, or thyroxine, is the main hormone secreted by your thyroid. It's biologically inactive and needs to be converted to T3 by your organs, such as the liver and kidneys. There are two types of T4 in your body:

  • Free T4 is the form that "freely" travels and enters your body's tissues where it's needed.

  • Bound T4 is a type of thyroxine that attaches to proteins, preventing it from entering your body's tissues. Over 99% of T4 is bound.

Since most T4 is converted into T3, it's more important to measure the amount of free T4 in the body. Any changes to your thyroid hormones will appear in T4 first.

The normal levels of free T4 depend on your age. In general, the normal range for adults is from 4.6 micrograms per deciliter (mg/dL) to 11.2 mg/dL. If your free T4 results are lower than this range, it may indicate hypothyroidism.

This test is often performed to confirm the findings of the TSH test.

3. Free T3 Test

T3 is the biologically active form of thyroid hormone. Your thyroid gland produces about 20% of it. The rest (80%) comes from the conversion of T4 by your liver and kidneys. Like T4, almost all T3 in the blood bounds to protein. The rest is free (unbound). Like free T4, low levels of free T3 indicate hypothyroidism. Since low T3 levels don't appear until hypothyroidism is advanced, the T3 test is of little help in making a diagnosis.

4. Thyroid peroxidase (TPO) antibodies

Once your doctor finds that you have hypothyroidism, they may perform thyroid peroxidase (TPO) antibodies. This test is done to determine whether your hypothyroidism is caused by Hashimoto's disease.

TPO is an enzyme that helps make T3 and T4 in your thyroid. Antibodies, on the other hand, are proteins that safeguard your body against germs like viruses and bacteria. However, when you have an autoimmune condition, it may mistake your healthy cells, such as TPO, as foreign.

TPO test detects antibodies against TPO in your blood. If TPO antibodies are present in your blood, it may suggest that your hypothyroidism is caused by an autoimmune disease, such as Hashimoto's disease.

What is the normal range of TSH?

The normal range of TSH varies from one laboratory to another. Some agree that it's 0.45 to 4.5 milliunits of hormone per liter of blood (mU/L), while others may agree on a different range. Moreover, normal TSH levels largely depend on your age, sex, and your health condition.

In general, levels between 4 to 10 mU/L are considered higher and may indicate hypothyroidism, but not always. Sometimes, high TSH levels are associated with other illnesses or older age.

Doctors usually treat your condition as hypothyroidism if your condition is higher than 10 mU/L. TSH levels within this range also often cause symptoms.

Can I have hypothyroid symptoms with normal TSH levels?

The answer is yes. Some people can have symptoms of underactive thyroid, but blood test normal. There's a complex reason behind this, but basically, the TSH test only measures one aspect of thyroid health. Therefore, having normal results doesn't guarantee that all symptoms will go away.

There is also some debate surrounding the accuracy of TSH testing. Research from 2018 suggests that TSH levels may indicate hypothyroidism in many cases but not in everyone.

What causes hypothyroidism with a normal blood test?

There are several factors that may cause you to still experience symptoms of hypothyroidism despite normal TSH levels, including:

Subclinical hypothyroidism

Subclinical hypothyroidism is a condition characterized by slightly elevated levels of TSH (thyroid-stimulating hormone) in the blood despite normal levels of thyroxine (T4). Although the exact numbers can vary across laboratories, a TSH level between 4 and 10 mU/L is often considered the threshold for subclinical hypothyroidism.

When you have subclinical hypothyroidism, you may or may not have symptoms. Since the symptoms are nonspecific and could be caused by other conditions, it can be hard to determine the symptoms of subclinical hypothyroidism.

Once diagnosed, patients with subclinical hypothyroidism may need to undergo more frequent thyroid testing to ensure that the condition doesn't develop into hypothyroidism.

Subclinical hypothyroidism in pregnant women

Pregnancy can have a significant impact on the thyroid, especially for women with thyroid disorders. The increased demands placed on the thyroid during pregnancy can result in elevated levels of TSH in the blood, leading to the development of subclinical or overt hypothyroidism.

Thyroid disease during pregnancy can also increase the risk of various complications, which is why doctors may advise treating it, even if your TSH levels don't meet the criteria for an official hypothyroidism diagnosis. Thyroid hormone replacement medication might be recommended if your TSH levels rise above 4 mU/L during pregnancy.

Secondary hypothyroidism

Secondary hypothyroidism is a less common type of hypothyroidism that occurs when the thyroid is functioning properly but the production of TSH in the pituitary gland is not. If your TSH levels decrease, your thyroid will produce fewer hormones. Sometimes, even if the pituitary gland does produce TSH, it may be biologically inactive, so it may not have an effect on your thyroid.

Secondary hypothyroidism can also be caused by problems with the hypothalamus, which produces thyroid-releasing hormone (TRH) that stimulates TSH production. Individuals with secondary hypothyroidism may have normal or slightly low TSH levels, and the diagnosis is usually based on low T4 levels.

Possible causes of secondary hypothyroidism include medications such as opioids, prednisone, and dopamine, radiation therapy to the brain, TRH resistance or deficiency, Sheehan's syndrome (a condition where excessive blood loss during childbirth damages the pituitary gland), lymphocytic hypophysitis (when white blood cells infiltrate the pituitary gland), and tumors on the pituitary gland or hypothalamus.

Vitamin or mineral deficiencies

Micronutrients, comprising vitamins and minerals, play a crucial role in maintaining optimal bodily function. Unlike macronutrients like carbohydrates, fats, and proteins, micronutrients are required in small quantities, but their absence can lead to significant health problems. These nutrients are necessary for a healthy metabolism, proper immune function, growth and development, strong bones, and many other vital processes.

Here are some of the most common micronutrient deficiencies:

1. Iron

Iron is a crucial mineral that is needed for healthy red blood cell production and oxygen transport in the body. Iron deficiency, also known as anemia, can cause fatigue, weakness, and difficulty concentrating, which can be symptoms similar to those of hypothyroidism.

2. Folate

Folate or vitamin B9 is important for cell growth and development, as well as for producing red blood cells. Folate deficiency can cause fatigue, weakness, and poor memory, which can also be similar to hypothyroidism symptoms.

3. Vitamin D

A deficiency in vitamin D can lead to symptoms similar to hypothyroidism, such as fatigue, muscle and joint aches, and skin and hair problems. These symptoms may occur because vitamin D helps regulate the immune system and is involved in various physiological processes.

5. Iodine

Iodine deficiency can cause symptoms similar to hypothyroidism, such as unexpected weight gain, fatigue, weakness, and hair loss. In fact, iodine is important in thyroid hormone production. Therefore, iodine deficiency can eventually lead to hypothyroidism.

Extreme stress

Stress can have a big impact on your health. It puts a heavy workload on our adrenal glands. These are two small glands that release hormones to help regulate our body's stress response, called cortisol. When our adrenal glands are overworked, they can produce too much of these hormones and cause symptoms like fatigue, headaches, poor sleep, mood swings, sugar cravings, dizziness, and more.

These symptoms can sometimes be mistaken for hypothyroidism, but they are actually caused by weakened adrenal glands. If you suspect you may have adrenal stress, you can take a saliva or urine test to check your cortisol levels.

Problems in the hypothalamic-pituitary-thyroid axis

The hypothalamic-pituitary-thyroid axis involves three parts of the body: the hypothalamus, pituitary gland, and thyroid gland. The hypothalamus is responsible for producing and releasing thyrotropin-releasing hormone (TRH), which stimulates the pituitary gland to produce thyroid-stimulating hormone (TSH). TSH, in turn, stimulates the thyroid gland to produce and release thyroid hormones, triiodothyronine (T3) and thyroxine (T4). This interplay between the hypothalamus, pituitary gland, and the thyroid gland is essential for maintaining a balanced and healthy level of thyroid hormones in the body.

When the hypothalamic-pituitary-thyroid axis is not functioning properly, your thyroid function tests may not be accurate.

A disorder in the hypothalamus or pituitary glands can lead to a condition called central hypothyroidism. It occurs when the thyroid gland doesn't receive enough stimulation from the hypothalamus or pituitary gland to produce enough thyroid hormones. This is different from primary hypothyroidism, where the thyroid gland itself doesn't function properly.

Central hypothyroidism can be caused by tumors, surgeries, or radiation exposure to the pituitary gland. In order to diagnose this condition, a doctor may perform a thyrotropin-releasing hormone stimulation test.

Problems with T4 to T3 conversion

T4 is an inactive thyroid hormone that needs to be converted to T3 for your body to use it. This conversion process is a crucial step in the regulation of thyroid hormones. Unfortunately, the conversion process doesn't always occur properly in some people. Some of the most common reasons There are several factors that can prevent the proper conversion of T4 to T3, such as insulin resistance, leptin resistance, environmental toxins, and acute or chronic dieting.

Poor T4 to T3 conversion also explains why some people don't improve with levothyroxine, the standard treatment of hypothyroidism. Since levothyroxine only provides T4, your body will have excess T4 but a lack of T3. Thus, you'll still experience symptoms even if your test results are normal.

What to do if your thyroid symptoms won't go away?

If your test results are normal, but you continue to experience symptoms of hypothyroidism, here are some solutions to consider:

1. Consider adding a T3 drug

If you are experiencing hypothyroid symptoms despite having normal TSH levels, it's important to consider additional thyroid hormone replacement therapy. This may include adding T3, such as liothyronine, to your treatment plan.

To determine if this may be beneficial for you, it's best to have your thyroid hormone levels checked. If your free T3 levels are low or sub-normal, despite having an optimal TSH, T3 medication may be an option to consider.

Research has shown that patients taking T4-only medication have lower T3 levels compared to those without thyroid problems and with similar TSH levels. Adding T3 to your treatment for hypothyroidism may help improve thyroid function, as higher T3 levels have been linked to better thyroid function.

2. Try natural desiccated thyroid (NDT)

Another option if you want to try adding T3 to your treatment is natural desiccated thyroid (NDT). Unlike levothyroxine and liothyronine, which only contain one synthetic thyroid hormone, NDT contains natural forms of both T3 and T4. The hormones are considered natural because they are derived from dried pig thyroid glands.

Because of its complex composition, NDT is preferred by many hypothyroid patients and is often considered the best thyroid hormone replacement medication. But despite its popularity among people, including Hillary Clinton, NDT can be hard to find. Some doctors even refuse to prescribe it because there is a lot of misconception about it.

If you want to try NDT but can't find it anywhere, one of the best options you can try is VitaliThy, a natural desiccated thyroid you can buy online. Not only does it contain complete thyroid hormones, but it's also safe for those who have an allergy to gluten, lactose, shellfish, fish, or eggs.

Conclusion: you can still have hypothyroid symptoms even with normal TSH levels

Though it may seem surprising, your thyroid stimulating hormone (TSH) levels can appear to be within the normal range on standard lab tests while still leaving an individual feeling anything but their best. While normal TSH levels can be a sign of healthy thyroid function, they are not always the most accurate indicator of how well your body is producing hormones.

There are several factors that can cause hypothyroidism symptoms despite normal TSH levels, including subclinical hypothyroidism, secondary hypothyroidism, micronutrient deficiencies, pregnancy, and extreme stress. People who continue to experience symptoms of hypothyroidism should speak with their healthcare provider about further testing and treatment options.

One of the best ways to deal with this problem is to add T3 to your treatment plan, and a great way to do that is by taking natural desiccated thyroid (NDT) in supplement form. A popular option is VitaliThy, which can be easily purchased online and contains both T4 and T3. With this NDT supplement, you can expect to regain optimal health and dance through life with energy and vitality in no time!

Wojciech Majda
Wojciech Majda

Leave a comment

Comments will be approved before showing up.

Also in Natural Desiccated Thyroid blog

What are my chances of getting pregnant with hypothyroidism?
What are my chances of getting pregnant with hypothyroidism?

July 17, 2023 13 min read

When it comes to getting pregnant, it's not just about the birds and the bees. There are actually a whole host of medical factors at play. One such factor is your thyroid function. It's time to shed light on an essential question: "How can hypothyroidism influence my chances of becoming pregnant?"
PCOS and hypothyroidism: what's the connection?
PCOS and hypothyroidism: what's the connection?

July 17, 2023 11 min read

How to boost metabolism with hypothyroidism: Metabolic thyroid supplement, exercises, and more
How to boost metabolism with hypothyroidism: Metabolic thyroid supplement, exercises, and more

July 17, 2023 9 min read

Hypothyroidism can be a challenging condition for everyone, but there are some simple steps you can take to boost your health! From metabolic thyroid supplements to exercises, this article will show you how to get your metabolism up and running again.

Sign up for our Newsletter