In People Without Known Thyroid Disease
A high TSH in people who are not undergoing thyroid disease treatment usually indicates the presence of primary hypothyroidism.
This is by far the most common form of hypothyroidism, and it occurs because the thyroid gland produces an inadequate amount of thyroid hormones. The pituitary gland senses these low levels and increases the production of TSH.
An elevated TSH may also occur with normal thyroid function due to the presence of antibodies, proteins made by the immune system.
What Can Affect Blood Test Results
Test results give healthcare providers part of the clinical picture. Each lab helps paint the clinical picture by giving evidence of certain conditions, or specific diseases. Blood lab test results can be affected by certain things including food and drinks.
A fasting blood glucose level or fasting lipid panel will not be accurate if you consume food or beverages 8 hours before lab collection. Collecting lab tests when you have eaten may give false data, thus making it important to be honest with your provider when collecting blood samples. If you do not fast, the results may not be accurate. In general, not fasting can be accounted for, so all you need to do is be honest and tell your doctor.
Other factors that can affect blood test results include:
- Vigorous exercise .
- Stress .
- Being ill .
- Medications can skew test results .
- Lab testing variations .
It is important to follow instructions when blood work is being collected. Verify with your doctor that you must fast prior to bloodwork or any other specific instructions. Your doctor will also ask for an updated list of medications and vitamins you take before blood tests are collected.
When Is A Thyroid Function Test Done
A thyroid function test is requested in a variety of situations, including if you:
- have signs or symptoms of an underactive thyroid gland or an overactive thyroid gland
- have signs of problems with your pituitary gland
- are taking medicines that can affect your thyroid function, such as amiodarone and lithium
- are pregnant
- have infertility problems .
It is also used to monitor your response if you are taking thyroid medication, such as thyroxine.
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Thyroid Testing: How It Works
Thyroid tests use a blood sample to measure various hormone levels. Thyroid-stimulating hormone , for example, is often measured to indirectly check if your thyroid gland is producing enough thyroid hormones. TSH levels are usually higher than normal if you have an underactive thyroid .
Thyroid function tests can also measure thyroid hormones like thyroxine to provide a better understanding of how low â or how high â your thyroid hormone levels are.
When Do You Need Treatment
Many hypothyroid patients feel at their best when theyre on medication and their thyroid levels are in the optimal TSH range of 0.5-2.00 , Dr. Henderson says. Since lab assays and ranges vary, the optimized levels for a patients specific lab can also vary. For elderly patients, the TSH target is in the 4.0 6.0 range.
Most doctors commonly treat their hypothyroid patients with a daily dose of levothyroxine , a man-made version of the T4 thyroid hormone made by the body, some doctors recommend using both T4 and T3 as the treatment option.
With thyroid medication, the dosing has to be just right, Dr. Henderson says. Too much or too little of the medication can lead to side effects that affect a patients health.
In patients who are diagnosed as hyperthyroid, treatment can include antithyroid medications such as methimazole, that works to control the overactive thyroid. Some patients are given radioactive iodine, which is given in pill form to gradually and safely shrink the thyroid.
If you are experiencing signs of an under- or overactive thyroid, seek professional medical advice from your doctor or a specialist in endocrinology about these tests and treatments.
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Bipoc And Graves Disease
Studies have found that Graves disease is more common in certain BIPOC populations.
A study of active duty U.S. military personnel published in JAMA found that the incidence rate ratio of Graves disease was significantly higher among Black people and Asian/Pacific Islanders compared with white people. This may be due to environmental exposures, genetics, or a combination of both, according to the study authors.
How To Measure Tsh Levels
The TSH test involves a healthcare professional drawing blood from a vein in the inner arm. They then send the blood sample to a laboratory for testing.
Usually, people do not need to prepare for a TSH test. However, if the doctor is testing the blood for more than one issue, a person may need to fast or prepare in another way. The doctor will provide this information beforehand.
If a person has abnormally high or low TSH levels, the doctor needs to run at least one other diagnostic test to identify the underlying cause. These tests look at levels of specific thyroid hormones and antibodies.
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Things That Can Affect Your Thyroid Function Results
Fasting Generally, you dont need to fast before doing a thyroid function test. However, not fasting is sometimes linked to a lower TSH level. This means your results might not pick up on mild hypothyroidism where your TSH levels are only mildly elevated.
Medications Some medications can interfere with your results so its important to tell your doctor about any drugs you take.
Pregnancy Being pregnant can also influence your results. So if youre pregnant make sure to discuss this with your doctor.
How Is Graves Disease Diagnosed
A diagnosis of Graves disease is generally made based on symptoms and a physical exam, according to the NIDDK. A blood test can confirm that you have hyperthyroidism and, in some cases, identify Graves disease as the cause.
- Radioactive iodine uptake test, whichmeasures the amount of iodine the thyroid collects from the bloodstream. If the test shows that your thyroid collects large amounts of iodine, you may have Graves disease.
- Thyroid scan, which shows how and where iodine is distributed in the thyroid. If you have Graves disease, iodine will show up throughout the thyroid.
- Ultrasound, which can reveal whether the thyroid gland is enlarged.
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What Is Thyroid Disease
Some diseases of the thyroid or pituitary gland cause the thyroid to make too much or not enough thyroid hormone:
- If the thyroid is overactive, it releases too much thyroid hormone, causing hyperthyroidism. The body use up energy more quickly than it should, and chemical activity in the cells speeds up. Symptoms include sweating, trembling, weight loss, and fast heartbeat.
- If the thyroid is underactive, it makes too little thyroid hormone, causing hypothyroidism. The body uses up energy more slowly, and chemical activity in the cells slows down. Symptoms include tiredness, feeling cold, constipation, dry skin, and slow height growth in children.
The Benefits Of Catching Hypothyroidism Early
Theres an early stage of hypothyroidism called subclinical hypothyroidism, where a blood test for TSH is slightly elevated but the thyroid gland is still producing enough thyroid hormones, says McConnell.
In our fertility clinic, the most common presentation is subclinical hypothyroidism, says McConnell.
Subclinical hypothyroidism doesnt usually disturb periods, but it can still lead to some irregular bleeding and complications in pregnancy, says Spencer. Eventually, without treatment, subclinical hypothyroidism may lead to overt hypothyroidism, causing more menstrual abnormalities and medical problems, she says.
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All You Need To Know About Reading Your Thyroid Function Test Report
Written by Dr Anitha Anchan | Updated : April 8, 2016 12:13 AM IST
The thyroid gland is a ductless gland in your neck. It secretes hormones which regulate your growth and development by controlling your food metabolism, energy usage, sleep patterns, etc. The thyroid stimulating hormone is produced by the pituitary gland. It stimulates the thyroid gland to produce the two important hormones -thyroxine and triiodothyronine . The two thyroid hormones circulate in the blood in two forms – bound to a carrier protein and unbound or freely circulating. The cells of the body use only the unbound T3 and T4. The T3 hormone is crucial in maintaining the metabolism and other functions of the body. Increase or decrease in thyroid hormone production can cause health issues.
Thyroid function tests what are they?
Thyroid function tests are blood tests that check how well your thyroid gland is functioning. They measure the levels of thyroid-stimulating hormone , triiodothyronine and thyroxine .
When is it recommended?
Reading your thyroid function test report
Normal range: 0.4 to 4.0 milli-international units per liter of blood
Normal range: 9 – 25 picomoles/litre
Normal range: 3.5 to 7.8 pmol/litres
Image source: Shutterstock
Reading Other Thyroid Test Results
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What Do The Results From My Thyroid Function Test Mean
Your doctor will discuss the results of your thyroid function test with you.An abnormal TSH usually indicates a deficiency or an excess of thyroid hormones available to your body, but it does not indicate why this is happening. An abnormal TSH result is usually followed by additional testing of FT3 and/or FT4 to investigate the cause.A high TSH result:
- often means an underactive thyroid gland
- can also occur if you have an underactive thyroid gland and are receiving too little thyroid hormone medication
- can indicate in rare cases a problem with your pituitary gland, such as a tumour.
A low TSH result:
- can indicate an overactive thyroid gland or damage to your pituitary gland that prevents it from producing TSH
- can also occur if you have an underactive thyroid gland and are receiving too much thyroid hormone medication.
Duration Of Graves Disease
If you are treating Graves disease with antithyroid medicine, your thyroid hormone levels may take several weeks or months to move into the normal range. The total average treatment time is about 12 to 18 months, but treatment can continue for many years.
According to the American Thyroid Association, 20 to 30 percent of people with Graves disease who take antithyroid drugs for 12 to 18 months experience a prolonged remission of their disease.
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How To Interpret Your Thyroid Labs
When it comes down to it, you are likely wondering what all your thyroid labs might mean and what they signify for your health.
Today, I am going to do a deep dive to break all of that down for you. To leave you with a clearer picture for your health. Especially when it comes to explaining the causes abnormal thyroid levels.
I definitely understand when things can be frustrating because they are important to your health, they are coming off as unclear.
Maybe they were not explained very well by your doctor. Or, perhaps the explanation simply did not make sense.
Was it hypothyroidism? Hashimotos? Graves disease? What is going on in your body, and what can you do to understand it and fix it? I want to go through all these super important tests with you.
Together, we can make total sense of them to better benefit your long-term health.
What Does The Test Measure
The TSH test measures thyroid-stimulating hormone, which is a hormone that prompts the thyroid to produce other hormones. The thyroid is a butterfly-shaped gland in your neck that makes the hormones triiodothyronine and thyroxine . T3 and T4 control your metabolism, or how your body uses and stores energy.
Although TSH acts upon the thyroid gland by binding to the TSH receptor, it is made in the pituitary gland. The pituitary gland is sometimes called the master gland, because it produces many hormones that control the functions of other glands in the body. The pituitary gland is able to sense when your T3 and T4 hormone levels are too low or too high. In response, it will produce more or less TSH to stimulate your thyroid gland to produce the right amount of hormones.
If your thyroid is underactive, you may have high levels of TSH as your pituitary gland tries to stimulate the thyroid to produce more T3 and T4. If your thyroid is overactive, your TSH may be abnormally low because your pituitary gland stops making TSH when your thyroid hormone levels are too high.
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Hypothyroidism Can Make Periods Heavy Absent Or Irregular
Hypothyroidism can put the brakes on ovulation a phenomenon known as anovulation resulting in heavy periods. In some women with uncontrolled hypothyroidism, this anovulation can lead to disordered growth and shedding of the uterine lining, causing unpredictable bouts of heavy bleeding from the uterus, says Jessica Spencer, MD, an associate professor of gynecology and obstetrics at Emory University School of Medicine in Atlanta. This can be monthly in some women and far apart in others.
Changes in prolactin levels can lead to thinning of the uterine lining and changes in how the pituitary gland controls the ovaries both can result in periods stopping completely, says Dr. Spencer.
Hypothyroidism can also change coagulation factors, increasing the risk of heavy bleeding.
Women of reproductive age with hypothyroidism may experience heavy periods, absent periods, or irregular periods, says McConnell, and the symptoms of menstrual irregularities will depend on the severity of the hypothyroidism.
Menstrual irregularities tend to be more common in women with severe hypothyroidism compared to mild hypothyroidism, says McConnell.
How Tsh Levels Change
TSH levels are not very intuitive. Why does a high TSH mean you have an underactive thyroid gland? Why do low levels means the gland is overactive?
Understanding exactly how the thyroid gland works can help.
Your thyroid gland produces thyroid hormone. When it functions properly, your thyroid is part of a feedback loop with your pituitary gland that involves several actions:
First, your pituitary gland senses the level of thyroid hormone that is released into the bloodstream.
Your pituitary then releases the special messenger hormone TSH, which makes the thyroid release more thyroid hormone. From there:
- If your thyroid doesn’t produce enough thyroid hormone, your pituitary triggers your thyroid to make more.
- If your thyroid is overactive and producing too much thyroid hormone, your pituitary senses that and slows or shuts down TSH production.
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Top 10 Thyroid Tests And How To Interpret Them
Medically reviewed and written by Izabella Wentz, PharmD, FASCP on August 25, 2021
Many cases of thyroid problems are missed because most doctors dont perform a comprehensive test panel. I spent almost a decade undiagnosed because I only had one marker tested. My thyroid condition was missed completely, leading me to deal with needless mystery symptoms like chronic fatigue, depression, anxiety, and many others, for far too long!
I have a copy of my lab results from 2008, before I was diagnosed with Hashimotos and still searching for a reason behind my exhaustion, hair loss, anxiety, and digestive issues. On this lab report, my TSH is at 4.5 IU/mL, and there is a note written from the doctor: Your thyroid function is normal, no need to do anything. Perhaps a TSH of 4.5 IU/mL would have been normal for a 95-year-old woman, but I was 25 and sleeping 12+ hours a night to feel rested! Of course, even as a pharmacist, I didnt think to question the doctor and most people dont.
If you suspect that you may have a thyroid condition, or know someone who does, this article will go over all of the most helpful tests that can help you identify a thyroid condition.
This article will also teach you how to understand your labs so that you can advocate for proper treatment for yourself.
In this article, Ill go over:
How To Read Lab Results
Usually, lab test results are displayed through a healthcare online portal in which you can access at any time. Laboratory tests follow strict guidelines on privacy and information sharing. These results can then be sent to your doctor or kept for personal use.
How do you read a blood report? When reading a blood report, you first need to understand what is being evaluated. The following lab tests are used to measure specific body functions:
- Complete Blood Count Labs used to evaluate your overall health and detect a wide range of disorders including infection, leukemia, and anemia.
- Chemistry Panel Labs used to evaluate electrolyte balance and status of major body organs.
- Lipid panel Labs used to evaluate cholesterol and risk for heart attacks and strokes.
- Liver panel Labs used to evaluate liver function and risk for liver disease.
- Thyroid-stimulating Hormone Labs used to detect TSH hormones and other thyroid diseases.
- Hemoglobin A1C Labs used to detect diabetes or pre-diabetes and monitor treatment over time.
Next, you will need to understand what negative, positive, and inconclusive means in regard to lab tests:
For example, your urine sample may result as positive for protein or WBCs, which is abnormal. Oftentimes the letter H will be listed next to your lab value, which means high value or higher than the average range. Furthermore, the letter L will also be listed next to the value to signify a low value, meaning lower than the average range.
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