Do I Have a Thyroid Problem?

Constant fatigue, cold hands, sluggish speech, dry skin, unexpected weight gain… Sound familiar? You might wonder if these are signs of menopause, or maybe you’re way too young for that. Surprisingly, the answer might lie in your thyroid.

The Thyroid: Your Body’s Energy Factory

Your thyroid may be small—just a butterfly-shaped organ at the base of your neck—but it plays a tremendous role in keeping your body in harmony.

Imagine your body is like a giant city. Every part of your body needs energy and supplies to keep working. In the middle of this city, there’s a special factory called the Thyroid Factory. This factory is super important because it makes these cargos called T3 and T4, also known as the thyroid hormones. Once the T3 and T4 cargos are ready, they are carefully packaged and shipped out via the bloodstream, the body’s transport network. Their destination? Every single tissue in the body, where they regulate vital functions like heart rate, digestion, and brain activity. However, when there is miscommunication during any point of the assembly line, production of T3 and T4 will slow down, and so do your body functions.

What Does it Feel Like: Hypothyroidism Symptoms

As mentioned above, your thyroid plays a vital role in controlling nearly every organ in your body by sending them signals in the form of thyroid hormones. When the thyroid slows down and produces fewer hormones than your body needs, everything else slows down too, leading to what’s often referred to as a “slowed metabolism”. As a result, you might experience symptoms like (1):

• Persistent fatigue: A lack of thyroid hormones can make even small tasks feel exhausting.
• Weight gain: With a slowed metabolism, the body burns fewer calories, causing weight to creep up despite no change in diet or activity level.
• Cold intolerance: Low thyroid function affects temperature regulation, often making you feel cold even in warm environments.
• Dry skin and brittle hair: Reduced thyroid hormones can decrease the renewal of skin cells, leading to dry, flaky skin and fragile hair.
• Constipation: A slower metabolism can also slow digestion, causing constipation.
• Muscle and joint pain: Without enough thyroid hormones, muscle strength and repair slow down, leading to aches, stiffness, and discomfort.
• Mood changes: Hypothyroidism can lower mood, leading to feelings of depression, low motivation, and brain fog.
• Anemia: Patients with hypothyroidism have less red blood cells, leading to more fatigue and weakness

These are all signs of hypothyroidism—”hypo” means “low”, so hypothyroidism simply means “low thyroid hormones”. Makes sense, right?

How to Read Thyroid Function Studies

When a thyroid problem is suspected, your doctor may order a thyroid function panel for you, which usually include the following lab tests:

• Free Thyroxine (FT3)
• Free Triiodothyronine (FT4)
• Thyroid stimulating hormone (TSH)
• Thyroglobulin antibodies (Anti-Tg)
• Thyroid peroxidase antibodies (Anti-TPO)
• Reverse T3 (rT3)

Knowing how to read these labs can help you understand how to take care of your thyroid! Feeling overwhelmed? Don’t fret, read the following story to help you figure out the ins and outs of these tests.

Remember the Thyroid Factory? Now let’s dive into the details of this bustling hub of activity that keeps your body’s engines humming. This factory is vital to your body’s operations, as it produces and ships the essential cargos T3 and T4 to tissues far and wide. Without these cargos, the body’s “machines” can’t run efficiently. So, let’s take a closer look at how this amazing operation works.

The Factory Floor

The Thyroid Factory is staffed by hardworking teams of factory workers known as thyroglobulin (Tg) and thyroid peroxidase (TPO). These diligent workers collaborate to produce T3 and T4, the prized cargos that keep your body energized and your metabolism functioning. T3 is the active form, while T4 is like a backup that can turn into T3 when needed.

Two types of T3 and T4 can be measured in the blood. While total T3 and T4 tell you the total number of cargos produced, free T3 and T4 tell you the number of cargos actually shipped out and used in the body, which are much more important to know.

Lab values: Normal ranges for FT3 are 2.0–4.4 ng/mL, and for FT4, they’re 0.8–1.8 ng/dL. Some functional health experts believe it’s best to aim for the higher end of these ranges, especially if you’re showing signs of thyroid issues, even if your levels are technically “normal” (2).

The Hitmen in the Shadows

Unfortunately, not everyone supports the Thyroid Factory’s success. Bad guys known as thyroglobulin antibodies (anti-Tg) and thyroid peroxidase antibodies (anti-TPO) lurk in the shadows. Although these names may sound intimidating, just think of it simply. If your name is John and I hire someone named Anti-John, his whole job is to get get rid of John. Therefore, the goal of the the “anti” bodies is to kill and get rid of the little workers in your thyroid.

These hitmen are produced by a confused immune system, attempting to assassinate the little factory workers, thyroglobulin, and thyroid peroxidase, halting production and leaving the body’s tissues deprived of their critical cargos. When these hitmen succeed, the factory slows down, and symptoms like fatigue, weight gain, and cold sensitivity can arise—a condition known as, you know it, hypothyroidism.

Lab values: While normal lab ranges for these antibodies are considered under 35 IU/mL, healthy people with no thyroid issues usually have levels closer to zero. Because technically, you wouldn’t want any hitmen at all in your precious thyroid factory!

When you have an abnormal level of these antibodies and paired with low thyroid hormone, you pretty much have Hashimoto’s Thyroiditis (an autoimmune disease where the immune system mistakenly attack your thyroid), the most common cause of hypothyroidism.

The CEO and the Control Room

At the top of this operation is the your brain, the CEO of your bodily functions. The CEO oversees all factories and ensures they are producing the right amount of goods. It communicates with the Thyroid Factory using TSH (thyroid-stimulating hormone)—think of it as urgent emails or phone calls.

• When the CEO notices the body running low on T3 and T4, it sends a flurry of emails (high TSH levels) to demand the factory speed up production.
• If there’s already plenty of T3 and T4, the CEO sends fewer emails (low TSH levels), signaling the factory to scale back.

Lab values: The optimal value of TSH is 1.90–2.90 mIU/L, a value that is linked to the lowest heart disease risk and mortality (3). Furthermore, most people without thyroid issues have TSH levels below 2.5 mIU/L (4), which is also the optimal value for women who are trying to conceive (TTC) (5).

The Quality Check: Reverse T3

Sometimes, the factory accidentally makes a package called reverse T3 (rT3) instead of regular T3. Reverse T3 is like a defective package that looks similar to T3 but doesn’t work properly. It’s a decoy that can confuse the body and prevent the good T3 from doing its job. If too much reverse T3 builds up, it’s like the delivery trucks are carrying packages that don’t work, and your body might start to feel sluggish even though the factory is producing plenty of goods. Doctors don’t usually check rT3 unless a patient isn’t responding well to thyroid medication, which may happen when the body is under some sort of stress, such as illness or emotional challenges.

Lab Values: Normal rT3 levels are typically 10–24 ng/dL (2).

What to Do Before Lab Testing

1. If you take biotin, also known as vitamin B7 (found in many multivitamins), stop using it two days before your thyroid test. Biotin can mess up the results and make your thyroid levels look abnormal (6). However, it’s generally a good idea to stop all your supplements for 2-3 days before lab testing.
2. If you’re pregnant or on birth control, higher estrogen levels can raise your total T4 and T3. To get the full picture of your thyroid health, make sure your doctor also tests your TSH and FT4 levels (7).

Other Factors to Consider

Keep in mind, sex and age can affect what is truly optimal. For example, in the elderly population, healthy aging means higher TSH and lower T4. In addition, optimal TSH levels are also different for a pregnant individual (8).

Certain groups are also at a higher risk for developing hypothyroidism. Women, for instance, are 5 to 8 times more likely than men to be affected, with older women being particularly susceptible (2). Ethnicity plays a role as well—studies show Black Americans tend to have lower TSH levels compared to White or Mexican Americans (2).

Regardless of the threshold used, diagnosing and managing hypothyroidism requires more than just a lab result. If your labs are “normal” but they’re on the edge of normal or almost abnormal and you feel awful, that doesn’t mean you don’t have a thyroid issue. People’s bodies don’t boil down to cut-offs. Every person is slightly different, so your symptoms are a crucial part of determining whether you need to treat your thyroid.

So, I Have an Underactive Thyroid: What to Do Next?

If you’ve been diagnosed with hypothyroidism, don’t worry—it’s a condition that can be managed with the right treatment and lifestyle changes. By working closely with your dietitian and endocrinologist, following your treatment plan, eating well, staying active, and managing stress, you can keep your thyroid in balance and feel your best. Keep in mind that regular check-ups and adjustments to your medication may be needed along the way. If you’re unsure if medication is right for you, head to our blog here. Check out our blog on thyroid medications.

Evaluating thyroid lab levels in the context of your symptoms and overall health is essential. A personalized approach ensures treatment addresses not only the numbers but also how you feel, paving the way for better thyroid health and well-being.

Therefore, it is the best to consult with a functional healthcare provider to figure out what are the optimal thyroid levels for you! Check out our service here to embark your thyroid health journey!

For more tips on thyroid health and living with hypothyroidism, please refer to, Fuel Your Thyroid: What is a Hypothyroidism Diet?, where we dive deeper into managing your condition day-to-day.