Does Thyroxine Treatment Have Side Effects
No good-quality research is available on the side effects of treating subclinical hypothyroidism with thyroxine, but it’s generally considered to be a well-tolerated drug. Because the body usually produces this hormone on its own, there are no problems if the dose is correct. If it’s too high though, side effects can’t be ruled out. Possible side effects include heart problems like or a racing heartbeat.
What Is A Normal Thyroid Level
Tests often used to assess thyroid hormone status include TSH and FT4 tests. The normal value for a laboratory test is determined by measuring the hormone in a large population of healthy individuals and finding the normal reference range. Normal ranges for thyroid tests may vary slightly among different laboratories, and typical ranges for common tests are given below.
TSH normal values are 0.5 to 5.0 mIU/L. Pregnancy, a history of thyroid cancer, history of pituitary gland disease, and older age are some situations when TSH is optimally maintained in different range as guided by an endocrinologist.
FT4 normal values are 0.7 to 1.9ng/dL. Individuals taking medications that modify thyroid hormone metabolism and those with a history of thyroid cancer or pituitary disease may be optimally managed with a different normal FT4 range.
Total T4 and Total T3 levels measure bound and free thyroid hormone in the blood. These levels are influenced by many factors that affect protein levels in the body, including medications, sex hormones, and liver disease. A normal Total T4 level in adults ranges from 5.0 to 12.0g/dL. A normal Total T3 level in adults ranges from 80-220 ng/dL.
Free T3 assays are often unreliable and not routinely used to assess thyroid function.
How Does Subclinical Hypothyroidism Develop
The way that subclinical hypothyroidism develops depends on a number of different factors including the TSH level: Slightly elevated TSH levels often return to normal on their own. But people who have highly elevated levels often develop symptomatic overt hypothyroidism within several months or years.
One study followed people with high levels of TSH over a period of two to three years. The participants didn’t have any symptoms or diagnosed thyroid disorders. They were divided into three groups depending on how high their TSH levels were. The study produced the following results:
- Slightly elevated TSH levels : Each year, 2% of the participants in this group developed overt hypothyroidism.
- Moderately elevated TSH levels : Each year, 20% of the participants in this group developed hypothyroidism with symptoms.
- Highly elevated TSH levels : Each year, 73% of the participants in this group developed overt hypothyroidism.
TSH levels that are slightly or only moderately elevated don’t necessarily need to be treated. Some people who have high TSH levels never even develop symptoms. It is also very common for TSH levels to return to normal in children and teenagers.
The probability that overt hypothyroidism develops from subclinical hypothyroidism is greater if the thyorid is enlarged and thyroid antibodies are detectable in the blood. And women generally have a higher risk than men.
Also Check: Thyroid Apple Cider Vinegar
Thyroid Surgery And Treatment As Causes Of Hypothyroidism
Thyroid treatment and surgery can lead to hypothyroidism.
Radiation treatment of the thyroid can also lead to hypothyroidism. Radioactive iodine is a common treatment for hyperthyroidism. It works by destroying the cells of the thyroid gland and decreasing the production of T4.
Radiation is also used to treat people with head and neck cancers, Hodgkins disease, and other lymphomas, which can lead to damage of the thyroid gland.
Facts About Hypothyroidism And Pregnancy
Hypothyroidism is a condition that is caused by an underactive thyroid gland. It may happen during pregnancy. Many symptoms of the condition are similar to pregnancy symptoms. For example, they can both cause fatigue, weight gain, and changes in menstruation. Having low thyroid hormone levels can also cause problems with becoming pregnant. It can also be a cause of miscarriage.
Also Check: Can You Take Collagen With Thyroid Medicine
What Should I Do To Prepare For A Thyroid Function Test
Thyroid function tests usually require very little preparation.
You don’t need to fast before the blood test. And it doesn’t matter if you have taken your thyroid medicine just before the blood test.
Tell your doctor if you are taking any medication, as some medicines can alter the test results and how they are interpreted.
It is also important to mention if you have had any X-ray tests that have used a special contrast dye, as this may contain iodine which can affect the results. Levels of thyroid chemicals also change in pregnancy, so tell your doctor if you are pregnant when the test is taken.
Note: all newborn children have their thyroid function tested as part of the heel prick test which is offered to all babies and undertaken when they are 5 days old. See the separate leaflet called Newborn Baby Screening Tests for more information.
Plus How To Get The Absolute Most Out Of Your Thyroid Meds
The time of day you take your thyroid meds, and how you store them, can make or break your thyroid disease management.
Levothyroxine is the name of all synthetic forms of the thyroid hormone T4. This manufactured hormone mimics the natural hormone produced by your thyroid and is prescribed as the primary treatment for hypothyroidism, or an underactive thyroid.
Levothyroxine dosage is highly individualized, and your dosage may change as you and your doctor work to find what works best for you. See our levothyroxine dosage chart below to get an idea of where your treatment might begin and when to expect your doctor to check for adjustments. Starting dosages are often calculated based on your weight, but because in some cases your thyroid still makes its own T4, some doctors will start you with a lower dosage to avoid over-treatment symptoms that mimic hyperthyroidism . They also may start you on a lower dose if your body might need extra time to adjust to the effects of hormone replacement. Your doctor will then check your thyroid stimulating hormone levels over the first few months to see if your dosage needs any adjustment. Hormone replacement therapy is usually a lifelong treatment, so you should get your TSH levels checked every year to ensure youre still taking the right dose.
Infographic by Lauren Hunter
You can find more information about levothyroxine, including dosage, here.
- Increased sweating
Recommended Reading: Apple Cider Vinegar And Thyroid
How Do You Know If Anything Is Working
The clearest, and often first, thing to change will be your TSH scores. A TSH score moving downward means that there is more thyroid hormone coming in.
Assuming that you are on thyroid medication, and assuming that you didnt recently change the dose, a lowering TSH means that you are making more on your own.
Heres a quick tip: I encourage people not to put a whole lot of weight into a single TSH reading. Its better to see a trend, so a sudden drop may not be telling the whole story.
In short, youll want to work with your doctor at this point to help lower your dosage so that your TSH can stay in a good range .
Underactive Thyroid: Deciding Whether Or Not To Treat Subclinical Hypothyroidism
Subclinical hypothyroidism means that the thyroid gland is still producing enough thyroid hormones. But some blood values may suggest the early stages of a hormone deficiency. Experts don’t agree on whether subclinical hypothyroidism should be treated. It’s not clear in which cases treatment would have advantages.
If you already have noticeable hypothyroidism, the thyroid is no longer producing enough thyroid hormones. Thyroxine is the most important of the thyroid hormones. It helps regulate many of the bodys functions to balance your metabolism. Too little thyroxine can cause a number of different health problems. The symptoms range from cold hands to physical weakness, difficulty concentrating and . Hypothyroidism can be treated easily by taking a tablet containing the thyroid hormone once a day. These tablets act to replace the thyroxine that is not being produced. This usually makes the symptoms disappear completely.
Because it doesn’t cause any symptoms, subclinical hypothyroidism isn’t noticeable. The TSH value is too high, but the thyroid is still producing enough hormones. This hormone is produced in the pituitary gland and acts as a trigger for the thyroid to start producing the thyroid hormones. TSH levels that are just a little too high may be the first sign of the early stages of hypothyroidism: The pituitary gland responds to lower levels of thyroid hormones by increasing TSH production to activate the thyroid.
Recommended Reading: How To Cure Thyroid Hair Loss
Raise Your Thyroid Hormones Naturally Today
What I want you to know is that all of this is well within possibility and that you may well be able to help raise your thyroid hormone naturally, all on your own.
I hope this gave you a great place to start, but if you still need some inspiration Id recommend trying the Thyroid Quiz today .
P.S. Whenever you are ready, here is how I can help you now:
What Is A T4 Test
T4 Tests A Total T4 test measures the bound and free thyroxine hormone in the blood. A Free T4 measures what is not bound and able to freely enter and affect the body tissues.
What does it mean if T4 levels are abnormal? Importantly, Total T4 levels are affected by medications and medical conditions that change thyroid hormone binding proteins. Estrogen, oral contraceptive pills, pregnancy, liver disease, and hepatitis C virus infection are common causes of increased thyroid hormone binding proteins and will result in a high Total T4. Testosterone or androgens and anabolic steroids are common causes of thyroid hormone binding proteins and will result in a low Total T4.
In some circumstances, like pregnancy, a person may have normal thyroid function but Total T4 levels outside of the normal reference range. Tests measuring free T4 either a free T4 or free T4 index may more accurately reflect how the thyroid gland is functioning in these circumstances. An endocrinologist can determine when thyroid disease is present in the context of abnormal thyroid binding proteins.
You May Like: Thyrokare For Dogs Side Effects
What Is Thyroid Hormone
Thyroid hormone is made by the thyroid gland, a butterfly-shaped endocrine gland normally located in the lower front of the neck. Thyroid hormone is released into the blood where it is carried to all the tissues in the body. It helps the body use energy, stay warm and keeps the brain, heart, muscles, and other organs working as they should.
Thyroid hormone exists in two main forms: thyroxine and triiodothyronine . T4 is the primary form of thyroid hormone circulating in the blood . To exert its effects, T4 is converted to T3 by the removal of an iodine atom this occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. T3 normally accounts for about 5% of thyroid hormone circulating in the blood.
Most thyroid hormone in the blood is bound by protein, while only a small fraction is “free” to enter tissues and have a biologic effect. Thyroid tests may measure total or free hormone levels.
Persistently Elevated Tsh Despite Thyroid Hormone Replacement
Poor compliance is the most common reason for continued elevation of the TSH level in patients receiving presumably adequate thyroid hormone replacement. Patients who do not regularly take their replacement medication and then try to catch up just before a physician visit may restore their free T4 levels to normal but continue to have an elevated TSH level.
Very rarely, patients have tissue-level unresponsiveness to thyroid hormone. This condition reflects a mutation in the gene that controls a receptor for T3, rendering it unable to bind with the hormone. The genetic mutation has been identified in only 300 families.22 In these patients, adequate amounts of thyroid hormone are produced but are ineffective. Consequently, the TSH level remains elevated, and the patients continue to have symptoms of hypothyroidism. These patients should be referred to an endocrinologist for further evaluation and management.
You May Like: Is Apple Cider Vinegar Good For Your Thyroid
Why Your Thyroid Hormone Levels May Be Fluctuating
If you have thyroid disease, you may experience some fluctuations in your thyroid hormone levels from time to time. These fluctuations can occur as your thyroid disease progresses, but other factors, such hormonal changes, and medication variations, can alter your thyroid hormone levels as well, producing a variety of symptoms.
When Should I Get A Tsh Test
TSH is often the first test doctors order when they suspect a patient has a thyroid disorder. Both hypothyroidism and hyperthyroidism are common disorders. All patients with symptoms of these thyroid disorders should have their TSH checked.
If you are having symptoms of these disorders, your doctor may order a TSH or a thyroid panel test. Symptoms of hypothyroidism include:
- Rapid or irregular heartbeat
- Loose, frequent bowel movements
TSH is also used to evaluate patients who are suspected to have other thyroid disorders, such as goiter, thyroid nodule, thyroid cancer, Graves disease, or Hashimotos thyroiditis. These disorders can cause hypothyroidism or hyperthyroidism.
Screening with TSH for hypothyroidism in adults is controversial. Screening means testing in the absence of symptoms. It is most beneficial when early detection and treatment of disease helps people avoid subsequent medical problems. Some organizations, such as the American Association of Clinical Endocrinology, the American Thyroid Association, and the Endocrine Society, favor routine screening for thyroid problems in adults without symptoms.
Because thyroid disorders can complicate pregnancy, screening with a TSH test during pregnancy is recommended for some women. Pregnant women without symptoms of thyroid problems may be screened if they:
Don’t Miss: Is Apple Cider Vinegar Good For Your Thyroid
How To Reduce Tsh Levels
This article was co-authored by Damaris Vega, MD. Dr. Damaris Vega is a board certified Endocrinologist. She graduated Magna Cum Laude from the Pontifical Catholic University of Puerto Rico with a BS in General Science and subsequently earned an MD from the Ponce School of Medicine, Ponce, PR. During medical school, Dr. Vega served as president of the Alpha Omega Alpha Medical Honor Society and was selected as her school’s representative for the American Association of Medical Colleges. She then completed a residency in Internal Medicine and a fellowship in Endocrinology, Diabetes, Mineral, and Metabolism at The University of Texas Southwestern Medical School. Dr. Vega has been recognized for excellent patient care multiple times by the National Committee for Quality Assurance and received the Patients’ Choice Award in 2008, 2009, and 2015. She is a fellow of the American College of Clinical Endocrinologists and is an active member of the American Association of Clinical Endocrinologists, the American Diabetes Association, and the Endocrine Society. Dr. Vega is also the founder and CEO of Houston Endocrinology Center as well as a principal investigator for multiple clinical trials at Juno Research, LLC.There are 12 references cited in this article, which can be found at the bottom of the page. This article has been viewed 109,771 times.
Reasons For Fluctuating Thyroid Hormone Levels
Thyroid disease can progress or stabilize as the year’s pass due to any number of reasons:
One of the most common contributing factors of fluctuation in your thyroid levels is your age. As we age, especially women, our thyroid function tends to slow down. According to Harvard Health, of women between the ages 35 and 65, “About 13% of women will have an underactive thyroid, and the proportion rises to 20% among those over 65”. A person’s age at the onset of a thyroid condition often plays a role in their treatment. Many of the symptoms associated with hypothyroidism resemble the typical side-effects of aging, which may delay treatment. Many women attribute their fatigue, weight gain, and brittle hair and nails to menopause instead of a thyroid issue. Therefore, they may not raise the issue with their doctor or seek treatment.
Medication dosage and potency
Your thyroid levels may also vary due to medication type, potency, and dosage. Variances such as a change in health plans, change in primary care physician, or change in thyroid medication formulations may lead to an adjustment in your thyroid medication dosage or potency. Switching to a new brand of thyroid medication may lead to fluctuation in thyroid levels as your body adjusts.
Interactions with other medications
Some prescription meds that can influence thyroid hormones:
We suggest regular monitoring of your thyroid function during the long-term use of any of the therapies listed above.
Also Check: Collagen For Thyroid
When Abnormal Thyroid Function Tests Are Not Due To Thyroid Disease
While blood tests to measure thyroid hormones and thyroid stimulating hormone are widely available, it is important to remember that no all tests are useful in all circumstances and many factors including medications, supplements, and non-thyroid medical conditions can affect thyroid test results. An endocrinologist can help you make sense of thyroid test results when there is a discrepancy between your results and how you feel. A good first step is often to repeat the test and ensure there are no medications that might interfere with the test results. Below are some common reasons for mismatch between thyroid tests and thyroid disease.
Non-thyroidal illness Significant illness, such as an infection, cancer, heart failure, or kidney disease, or recent recovery from an illness can cause changes transient changes in the TSH. Fasting or starvation can also cause a low TSH. An endocrinologist can help to interpret changes in thyroid function tests in these circumstances to distinguish non-thyroid illness from true thyroid dysfunction.
Test interference Biotin, a common supplement for hair and nail growth, interferes with many thyroid function tests and can lead to inaccurate results. Endocrinologists recommend stopping biotin supplements for 3 days before having a blood test for thyroid function.