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2023-10-26 22:12:56

What is TSH Reflex and Why Does it Matter?

Your thyroid gland might be tiny, but it's got a big job to do. Many of us get yearly blood tests to determine if our thyroid function is healthy and if not, what we need to do to fix it. Your blood test results might give you all sorts of information. Namely, you might see something called "TSH reflex." What does this mean and how can you tell if you're in the normal range?

This blog will answer these questions and more!

What is TSH with Reflex?

This is more of an abbreviated name. Technically, we're referring to TSH with reflex to free T4.

But what on earth does that mean?

Thyroid Stimulating Hormone

Let's back up! TSH stands for "thyroid stimulating hormone." This is one marker of your thyroid function. If your thyroid stimulating hormone is too low or too high, it could indicate some sort of thyroid disorder, like subclinical hypothyroidism, subclinical hyperthyroidism, central hypothyroidism, or central hyperthyroidism.

Free T4

We should also briefly discuss what free T4 is. T4, also known as thyroxine, is the main hormone that your thyroid gland produces. Free T4 is any free thyroxine that's not attached to the protein in your blood.

Putting it All Together

A TSH with reflex to free T4 test assesses your thyroid function when your healthcare provider suspects that your pituitary gland is not involved. (The pituitary gland makes TSH, which tells the thyroid gland to make T4. Sometimes, pituitary gland tumors can cause the thyroid to become overactive, making too much T4.)

TSH and TSH Reflex to Free T4 are Not the Same!

Note that a thyroid stimulating hormone test and a TSH reflex with a free T4 test are two different things. Healthcare providers will typically start with a thyroid stimulating hormone blood test. If you do not fall within optimal TSH ranges, then they might follow up with a blood test for free T4 to gain more insight.

Blood sample for thyroid function testing

What are the Normal Ranges for TSH with Reflex to Free T4?

It's important to note that "normal" levels can vary from person to person. The normal reference range can vary by lab, provider, and patient. However, the American Thyroid Association says that the normal value range for TSH is somewhere between 0.4 and 0.5 mU/L on the low end and 4.0 to 5.5 mU/L on the high end.

What about free T4? The typical range for free T4 in adults is 0.8 to 1.8 nanograms per deciliter (ng/dL). If your free T4 is higher, it could be a sign of an overactive thyroid. Conversely, not enough free T4 could indicate a thyroid that can't keep up.

Bear in mind that just because your blood tests show that you have normal TSH and T4 levels, that doesn't mean they're the optimal levels for you.

If you're on the very low end or the very high end of the range and you're experiencing symptoms of thyroid dysfunction, talk to your healthcare provider! Even within range, too much thyroid hormone (or not enough thyroid hormone) can cause symptoms.

How Do I Know if My Thyroid Gland is Struggling?

If you think you might be dealing with some sort of thyroid disease, what signs should you look out for?

Well, that depends. Let's talk about the various types of thyroid disorders.

5 Types of Thyroid Disorders

Your thyroid disorder symptoms will vary based on whether your thyroid gland is producing too much thyroid hormone or not enough.

1. Hyperthyroidism

This occurs when the thyroid gland makes too much thyroid hormone. Symptoms vary but can include sweating (making it especially difficult to tolerate heat), unintentional weight loss, anxiety, and irregular heartbeat.  

2. Hypothyroidism

This happens when the thyroid gland doesn't make sufficient thyroid hormone. Symptoms include depression, fatigue, weight gain, and stunted growth in children.

The cause is usually an autoimmune disease. In other words, your body produces antibodies that attack the gland, hampering thyroid function.

Read our blog on hyperthyroidism vs hypothyroidism.

3. Hashimoto's Thyroiditis

This is an autoimmune disease that destroys the hormone-producing parts of the thyroid gland. When these cells are destroyed by the immune system, the thyroid may first leak thyroid hormones, causing hyperthyroidism. But it eventually switches to hypothyroidism once it runs out of hormones. It therefore causes the symptoms of hypothyroidism, including fatigue, dry skin, constipation, hair loss, and depression, among others. The long-term inflammation of the gland can cause a "goiter," which is just the term for an enlarged thyroid.

4. Thyroid Cancer

There are various types of thyroid cancer. Fortunately, most of them can be successfully treated! Be sure to have abnormal masses or nodules monitored as directed by your healthcare provider.

5. Postpartum Thyroiditis

In this case, the thyroid gland becomes inflamed after giving birth, and hypothyroidism or hyperthyroidism can develop as a result, throwing the amount of thyroid hormone in your body out of whack, which usually lasts several weeks to a few months

Approximately 20 million Americans have some sort of thyroid disease, and it's often hereditary. The good news is that whether you have an underactive thyroid or an overactive thyroid, it is very treatable.

Start with a blood test to see where your thyroid hormone levels are at. Check your TSH and free T4. This will help your healthcare provider determine whether or not you might benefit from thyroid medication.

If there is concern for tumors, cysts, or goiters, your healthcare provider might recommend an ultrasound, too.

Patient getting an ultrasound to assess thyroid function

How to Check TSH with Reflex to Free T4

Thyroid tests are done through simple blood draws.

eNational's Thyroid Health Panel can help determine if you have an underactive or overactive thyroid. It checks your TSH levels, free T4, and T3 (which is not bound to protein in the blood, unlike T4).

TSH test results are usually available within one business day. We have more than 2,000 testing locations across the United States. Find a lab near you.

Will I Need to Be on Thyroid Hormone Medication Forever?

This is tough to answer since everyone is so different. If you're dealing with an underactive thyroid, you will likely be on medication for life. People with an underactive thyroid typically take levothyroxine, which is just replacement therapy.

This is also the case in the extreme scenario of needing to get your entire thyroid removed. Your body can no longer produce thyroid hormone on its own. So, medication is necessary to support your health.

However, in other cases, the need for medication can indeed be temporary since abnormal thyroid hormone levels can sometimes find ways to balance themselves out.

Interestingly, this can even be true with partial thyroid removal. The remainder of the gland can sometimes get the job done all on its own.

If you're taking medication as part of your thyroid treatment, it's vital that you work with your healthcare provider in the event of getting off your medication. Do not stop taking it on your own, without their guidance. This can harm your thyroid hormone levels and lead to dangerous symptoms.

Also note that if you're dealing with thyroid hormone problems, yearly or even twice-yearly bloodwork might be necessary for the foreseeable future and possibly indefinitely.

This is because, over time, our thyroid hormones can fluctuate. You might feel amazing now and not too great in a year. Get your thyroid hormones checked at regular intervals to maintain good health!

Can I Improve My Thyroid Function with Lifestyle Changes?

Yes! A lot of lifestyle habits that are good for your overall health are also, as a result, good for your thyroid hormone levels. Here are a few general tips:

Find Healthy Ways to Cope with Stress

A little bit of stress is normal and even good for us. However, when it gets out of control, it can lead to a number of health problems.

More specifically, when you're stressed, your body releases a hormone called cortisol. Excess cortisol can interfere with thyroid hormone and exacerbate any symptoms you're already experiencing.

Try meditating, journaling, or spending time in nature. Stress management also means getting enough sleep. Your thyroid hormone levels depend on it.

Man meditating to manage stress

Fuel Your Body Right

Eat a balanced diet and your thyroid hormone levels will thank you.

Try to keep highly processed foods to a minimum. Aim to eat nutrient-dense foods 80% of the time.

If you have an iodine deficiency, you might want to steer clear of cruciferous vegetables like broccoli and cabbage. They can interfere with the production of thyroid hormone.

If you think you need dietary changes as part of your thyroid treatment, speak with your provider first.

Keep it Moving

We have become sedentary creatures who spend most of our time indoors. This is not what the human body was meant to do!

Particularly if you're experiencing lethargy or weight gain, regular movement can help. Aim for 30 minutes three times a week, and you just might notice a big improvement.

Please keep in mind that these lifestyle changes can be a great complement to your everyday habits. However, you should still visit your healthcare provider to check your thyroid hormones — including your TSH with reflex to free T4 — through bloodwork.

Even with these changes, thyroid tests, bloodwork, and even medication might still be necessary.

Get Ahead of Your Thyroid Issues

We know that managing your thyroid issues can be overwhelming, especially when your symptoms are getting the best of you. There are also a lot of terms that might be unfamiliar to you. Free T4, subclinical hypothyroidism, TSH with reflex... it's all so confusing!

Just take it one step at a time.

Optimal thyroid production can significantly improve your mental and physical well-being. If you think that your thyroid levels might not be where they need to be, order a thyroid panel blood test, speak with a clinician about your thyroid test results, and work together to come up with a treatment plan that makes sense for you.

Ready to order your thyroid tests? eNational Testing is here to help. Find a testing center that's convenient for you and order your TSH test today. We look forward to serving you.