Frequently Asked Questions
Answered by Monique Atkinson – Patient Advocate © 2016 Monique Atkinson
Is a low TSH safe if you are on thyroid hormone replacement therapy?
New research shows it may be safe to have a low TSH level between 0.04 mIU/L and 0.4 mIU/L which is below the normal reference range. The first population based study monitored 16,426 patients who were on thyroid hormone replacement therapy between 1993 and 2001. The research was presented by Graham Leese from the University of Dundee in Scotland, at the Society for Endocrinology BES 2010 in Manchester.
The study looked at how variations in patients’ TSH levels affected their long term health. Patients who had a low TSH as defined above did not show an increased risk of heart disease, bone fractures or dysrhythmias. The findings confirm it may be safe to take higher doses than currently recommended. Some patients only feel well when their TSH is low with thyroid hormone levels at the upper end of the normal reference range.
According to this particular study, patients with a suppressed TSH, which was defined as a level below 0.04 mIU/L and a raised TSH over 4.0 mIU/L, were at an increased risk of heart disease and bone fractures. However newer studies on the osteoporosis controversy show that people on thyroid hormone replacement therapy with a low or even suppressed TSH don’t have an increased risk of osteoporosis.
I was diagnosed with Hashimoto’s. My TSH is normal and I have many symptoms of an underactive thyroid, but my doctor says I don’t need any treatment yet. Should I see another doctor?
Yes, it has been well documented that subclinical hypothyroidism or mild thyroid failure can be detrimental to our health. Some people experience classic symptoms when they are in the early stages of thyroid disease, but for some people mild thyroid failure may be associated with symptoms such as depression, anxiety, loss of memory, loss of cognitive function, systolic and diastolic cardiac dysfunction, raised levels of total and LDL cholesterol, an increased risk for the development of atherosclerosis and subtle neuromuscular abnormalities.
Early treatment and optimal treatment of thyroid hormone replacement therapy can reverse these effects and it can also improve the quality of life for many people.
In many cases the opportunity for a proper diagnosis or optimal treatment of hypothyroidism is lost with the current reference range of the TSH, because it is too wide. Large population based studies have shown that people who are in the early stages of thyroid disease are included in the normal reference range.
Experts have been debating about the guidelines of diagnosis and treatment of hypothyroidism for several decades and for many doctors it remains unclear when to treat or not to treat.
The NACB recommended an upper limit of 2.5 mIU/L for the TSH in 2002, [link]
The AACE published a press release in 2003 which stated that more than 13 million people suffered from thyroid disease in the USA, but remained undiagnosed, because the reference range for the TSH was too wide. As a result a new upper limit of 3.04 mIU/L was recommended for the TSH, [link]
In 2012 the AACE took an even more conservative view and recommended an upper limit of 4.12 mIU/L for the TSH, even though it was well established that people with mild thyroid failure could be included in this new recommended reference range for the TSH, [link]
Doctors are therefore urged to use their best clinical judgement and in the latest AACE’s guidelines published in 2012 it is stated that the recommended guidelines may not be appropriate for everyone.
Most experts agree that the upper limit for the TSH should be 2 mIU/L. Blood test results of actual thyroid hormone levels (Free T4 and Free T3) can often provide better information. It needs to be remembered that people with a healthy thyroid have optimal levels of ‘Free T4’ (in the upper third of the normal range). People with lower levels of ‘Free T4’ (but within the normal range) may be in the early stages of thyroid disease regardless of the TSH value.
Therefore treatment should be based on each patient’s individual circumstances and treatment (a therapeutic trial of thyroxine) should be considered for people with lower levels of ‘Free T4’ (within the normal range or below the normal range) and classic signs and symptoms of hypothyroidism especially for;
- Anyone with positive thyroid antibodies,
- People with a history of autoimmune thyroid disease,
- Women who are planning a pregnancy (optimal thyroxine levels are needed the baby’s brain development especially in the first trimester and optimal levels may also prevent infertility and miscarriages and other pregnancy-related complications,
- People with increased cholesterol levels or other risk factors for cardiovascular disease.
- Children and adolescents as optimal thyroxine levels play an important role in growth and learning abilities.
Spencer, C. et al. (2007). National Health and Nutrition Examination Survey III Thyroid-Stimulating Hormone (TSH)-Thyroperoxidase Antibody Relationships Demonstrate That TSH Upper Reference Limits May Be Skewed by Occult Thyroid Dysfunction: The Journal of Clinical Endocrinology & Metabolism: Vol 92, No 11. (2007). The Journal of Clinical Endocrinology & Metabolism. [online] Available at: [link]
McDermott, M. and Chester Ridgway, et al. (2001). Subclinical Hypothyroidism Is Mild Thyroid Failure and Should be Treated: The Journal of Clinical Endocrinology & Metabolism: Vol 86, No 10. (2016). The Journal of Clinical Endocrinology & Metabolism. [online] Available at: [link]
Asvold, B. et al. (2007). The association between TSH within the reference range and serum lipid concentrations in a population-based study. The HUNT Study. - PubMed - NCBI. [online] Ncbi.nlm.nih.gov. Available at: [link]
Galofré, J. et al. (2013). The Incidence and Prevalence of Thyroid Dysfunction in Europe: A Meta-Analysis: The Journal of Clinical Endocrinology & Metabolism: Vol 99, No 3. (2013). The Journal of Clinical Endocrinology & Metabolism. [online] Available at: [link]
Hollowell, J. et al. (2002). Serum TSH, T(4), and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). - PubMed - NCBI. [online] Ncbi.nlm.nih.gov. Available at: [link]
Practitioners, T. (2016). RACGP - Hypothyroidism - Investigation and management. [online] Racgp.org.au. Available at: [link]
Spencer, C et al. (2002) NACB, Laboratory Support for the Diagnosis and Monitoring of Thyroid Disease [online] Available at: [link]
Garber, J. et al. (2012). ATA/AACE Guidelines – Clinical Practice Guidelines for Hypothyroidism in Adults: Co-sponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. [online] Available at: [link]
American Association of Clinical Endocrinologists. (2003). Press Release – Over 13 million with thyroid disease remain undiagnosed. [online] EndocrineWeb. Available at: [link]
I have Hashimoto’s and I take thyroxine, but I still don’t feel well. Will I ever feel well again?
The most common reasons why you may not feel well on thyroxine are as follows;
- You may not be getting enough thyroxine, because your doctor may be too focused on the TSH test.
- You may be taking too much thyroid hormone, which is evident by clinical signs, such as hot sensitivity, palpitations, fast resting pulse, weight loss or weight gain, change in appetite, frequent loose stools, inability to hold your fingers still etc.
- If you are on full replacement therapy you may just need a combination of thyroxine (T4) and triiodothyronine (T3), the two main hormones produced by a healthy thyroid gland. Conventional medicine can prescribe thyroxine and Tertroxin (artificial T4 and T3). However most doctors are not familiar with Tertroxin. Tertroxin is available on the PBS, but it is an authority script which means that the doctor needs to state the following; “replacement therapy for hypothyroid patients who have documented resistance to thyroxine sodium”. Integrative practitioners can prescribe desiccated thyroid hormone or slow release T3 capsules made by compounding pharmacies.
- You may have other underlying issues, such as nutritional deficiencies. For example (low levels of iron, B12, vitamin D, selenium, tyrosine, magnesium etc.)
- You may suffer from adrenal insufficiency. This can happen if your adrenal glands are no longer producing adequate amounts of cortisol. Alternative medicine believes most people with hypothyroidism have some sort of adrenal dysfunction. However, in practice most hypothyroid people actually have high or excessive levels of cortisol.
- You may have other underlying conditions which have not been diagnosed. For example, you may suffer from coeliac disease or non-coeliac gluten intolerance, rheumatoid arthritis or type 2 diabetes etc.
- Dietary factors, such as too many goitrogens in the diet or too little or too much iodine.
- You take iron, calcium or fibre supplements within 3 hours of thyroxine which interferes with the absorption of thyroxine.
Most people who are in the early stages of the disease do well on thyroxine only if the dose is right. However, studies have shown that people on full replacement therapy are more likely to experience symptoms of an underactive thyroid on thyroxine only.
Is there a cure for Hashimoto’s?
No, there is no cure, but replacing thyroid hormone is ESSENTIAL. We cannot live without thyroid hormone.
Is there a connection between thyroid disease and gluten?
What doctors specialize in thyroid disease?
General practitioners can diagnose and treat autoimmune thyroid disease. Sometimes patients are referred to endocrinologists or thyroidologists (doctors who specialise in thyroid disease). For nodules, goitres and thyroid cancer you may be referred to an endocrine surgeon as well.
© 2016 Monique Atkinson
Disclaimer The information provided is for educational purposes only and is not intended to be medical advice. The contents must not be relied upon in place of advice and treatment from a qualified medical practitioner. THYROID WA SUPPORT GROUP INC. and the author disclaim any liability whatsoever.