July 18, 2022

How Should I Prepare for a TSH Blood Test?

Key Takeaways

  • Thyroid-stimulating hormone (TSH) or thyrotropin, is a substance produced in the pituitary gland. It regulates the hormones made by the thyroid gland. 
  • A TSH blood test measures the thyroid levels in your body and will typically be ordered by a doctor if you are experiencing symptoms of a hormone imbalance. 
  • Hyperthyroidism is a condition where the thyroid is producing too much thyroxin. Hypothyroidism is a condition where the thyroid is producing too little thyroxin. 
  • Fasting is not required before a TSH blood test and maintaining healthy sleep patterns, staying calm and relaxed is recommended for accurate test results.

There’s a saying that something as small as the flap of a butterfly’s wings can cause a tornado on the other side of the world. Although this phrase is a bit of an overstatement (we hope), there is a small butterfly-shaped gland near the base of your neck that has a profound effect on regulating everything from your body’s temperature, heart rate, to your metabolism — the thyroid.

Before we jump into the thyroid, we need to understand the hormone that stimulates it. This hormone is known as Thyroid-stimulating hormone, or TSH, and in this article, we will explain what happens during a TSH test so you can prepare for your next lab appointment.

What Is TSH?

Thyroid-stimulating hormone (TSH), also known as thyrotropin, is a substance produced in the pituitary gland. It regulates the hormones made by your thyroid gland. And these thyroid hormones affect just about every gland in your body.

Not only can thyroid hormones slow down or speed up your heart rate, but they also control the rate at which you burn calories. When your thyroid is not functioning properly, it can affect your wellness.

If you have elevated TSH or a low TSH value, your thyroid gland may be producing too much of the hormone thyroxin. This can cause hyperthyroidism. This condition speeds up your metabolism and causes unwanted weight loss and irregular heart rhythms.

If your thyroid gland produces too little thyroxin, this can cause hypothyroidism. This condition slows down your metabolism causing unwanted weight gain, fatigue, and sensitivity to cold temperatures.

Your doctor will order a TSH test to check your thyrotropin levels if you are experiencing symptoms of a hormone imbalance. 

How Do You Know If Your Thyroid Gland Is Healthy?

Like we mentioned earlier, the thyroid is a small, butterfly-shaped gland located at the base of your neck, just below your Adam’s apple. 

Keeping your thyroid gland healthy is important because, among other things, it regulates your metabolism. This is the process that converts your food into energy to power your body’s systems. To control your metabolism, your thyroid gland uses two specific hormones, T3 (triiodothyronine) and T4 (thyroxine).  

Once these hormones enter your bloodstream, they are monitored by your pituitary gland (located at the base of your brain). If the pituitary detects that your thyroid hormones are too high or too low, it will release its own hormone to regulate them. This is called thyroid-stimulating hormone (TSH).

If your healthcare provider suspects that your thyroid gland is unable to make the right amount of hormones and you have a thyroid disorder, they will order a TSH test.

This is a thyroid function test that measures low and high TSH levels in your blood to detect thyroid problems. The test results will enable your physician to diagnose whether you have an overactive or underactive thyroid and treat the problem. 

According to the American Thyroid Association, possible causes of hypothyroidism (underactive thyroid) include:

  • Autoimmune disease (primary hypothyroidism)
  • Radiation treatment
  • Hashimoto’s thyroiditis (inflammation and thyroid nodules)
  • Thyroid cancer
  • Too little iodine
  • Goiter

Possible causes of hyperthyroidism (overactive thyroid) include:

  • Graves’ disease (the most common cause)
  • Thyroiditis (antibodies mistakenly target components of the thyroid gland)
  • Too much iodine
  • Goiter
  • Benign pituitary tumor

What to Do Before Your TSH Test:

It’s important to prepare for your TSH test in advance, so you can make sure your results will be as accurate as possible. Several things can affect the test’s outcome, such as:

  • Diet/fasting: If you fast before your TSH test, this can produce higher TSH levels compared to a test done without fasting, and this can make it difficult for your doctor to accurately diagnose your condition. 
  • Supplements: Some nutritional supplements may affect the accuracy of your TSH test. For example, biotin can cause a reading of falsely low TSH levels.
  • Pregnancy: Your normal thyroid condition and activity changes during pregnancy and your TSH level will tend to increase as your approach your third trimester.
  • Stress: Because stress increases your body’s production of the hormone cortisol, this can, in some instances, reduce your level of TSH. 
  • Sleep deprivation: If you suffer from insomnia this can increase your TSH level.

Because consistency is the key to getting accurate TSH test results, you must try to keep your hormone levels as normal as possible prior to your blood test. This means, not fasting before your test, trying to maintain a healthy sleep pattern, staying calm and relaxed, and letting your doctor know if you are pregnant. 

What to Do During Your Blood Test:

Before taking your blood sample, your Getlabs Specialist will make sure you are sitting or lying in a comfortable position. Follow their instructions and use these tips to ensure you have a pleasant experience:

  • Disclosure: Let the specialist know if you are taking any medications, have had any recent illness, or have had an unusual reaction to a blood test in the past (such as fainting, severe bruising, or swelling).
  • What to expect: Your specialist will tie a tourniquet around your upper arm to expose the veins on your inner arm. They will insert a needle with a test tube attached to draw your blood. When the sample has been collected, your specialist will remove the needle and apply pressure to the needle site for a few seconds. They will then cover it will a small dressing. 
  • Stay calm: You can remain calm during your blood test by taking deep breaths, listening to relaxing music during your blood draw, and looking away while the specialist inserts the needle into your vein and takes your blood sample. 
  • Take it easy: After the test, your specialist will apply a dressing to the needle site. You should leave this on for at least fifteen minutes. Avoid strenuous activity or heavy lifting for two hours after the test and do not put any pressure on your arm. 

What to Do While Waiting for Your Results:

Getlabs will deliver your blood sample for a lab test. At the laboratory, your blood will be tested to see if your levels of TSH are within the normal range. Typically, you will receive your results within 5-7 working days. Once available, you can view your results on your laboratory's patient portal for your laboratory:

While you are waiting for your test results, you can monitor yourself to see if you notice any changes in your body as unusual weight loss or weight gain.

What Your Test Results Mean:

The reference range for a healthy level of TSH is 0.4 to 4.0 milliunits per liter (mU/L). A higher TSH level means that your thyroid gland is not producing enough hormones. This condition is called hypothyroidism. 

A lower level of TSH means that your thyroid is producing too much hormone. This condition is called hyperthyroidism. Your TSH test will not explain why your hormones are unbalanced. Your healthcare provider will need to order more tests, such as a free T3 and free T4 test, to find out the underlying cause.  

Types of Thyroid Disease:

There are several different types of thyroid dysfunction, but the two most common ones are hypothyroidism and hyperthyroidism. The symptoms are as follows.

Symptoms of hypothyroidism (underactive thyroid)

  • Unintentional weight gain
  • Fatigue
  • Dry skin
  • Constipation
  • Unusual sensitivity to cold
  • Muscle weakness
  • Puffy face

Symptoms of hyperthyroidism

  • Unintentional weight loss
  • Rapid or irregular heart rhythm
  • Unexplained increase in appetite
  • Irritability and anxiety
  • Irregular heartbeat

Get At-Home TSH Tests with Getlabs.

If your doctor has recommended you take a TSH test, Getlabs can help you make it happen. You’ll love our service because it’s simple and convenient. 

All you need to do is call to book a home visit and one of our local specialists will make a visit to your home. Your sample will be collected professionally and efficiently while you relax, and we will make sure it gets to the lab for testing. You can save time and rest assured that your samples will arrive at the right place on time. 

All you do next is wait for your results.

This page is provided for educational and informational purposes only and does not constitute the provision of medical advice or professional services. The information provided should not be used for diagnosing or treating a health problem or disease, and those seeking personal medical advice regarding any of the tests and conditions referenced above are advised to consult with a licensed clinician. Always seek the advice of your qualified health provider regarding a medical condition and do not disregard professional medical advice or delay in seeking it because of any information on this page. If you think you may have a medical emergency, immediately call 911 or go to the nearest urgent care center or hospital.

Book an at-home lab collection

Getlabs sends a nearby medical specialist to you to collect your labs for Labcorp and Quest. Available same-day, nationwide.

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