by Dr Jess Braid

what is hypothyroidism?

what is hypothyroidism?

 Our thyroid glands are located in our neck. Its main job is to produce hormones that regulate our metabolism. When our thyroid is out of sync, it creates one of two conditions:

Hyperthyroidism, which is where the gland is overactive and produces too much thyroid hormone

Hypothyroidism, where the gland is underactive and doesn’t produce sufficient thyroid hormone.

In this article, we will look at hypothyroidism (also known as an underactive thyroid) and how it can be treated.

The thyroid gland produces hormones that affect your metabolism. Think of it like a car accelerator. If you have an overactive thyroid gland, it is like you are pressing the accelerator too hard – everything is revved up. Conversely, an underactive thyroid is like pressing the brake too hard – everything is slowed down.

The brain produces TSH – Thyroid Stimulating Hormone, which sends a message to the thyroid gland to produce thyroid hormone. The thyroid produces thyroid hormone in two forms. The two main types it produces are called T3 and T4. It also produces smaller amounts of the hormones T1 and T2. The medical profession is still learning about these hormones and how they work, but they believe that T2 may be important in fat burning, blood sugar control and losing weight,1 while T1 may have a protective role for our hearts.2

85% of the hormone produced by the thyroid gland is T4 (thyroxine), but it is relatively less active than its counterpart T3, yet T3 is much more active in the ways it affects the body. T4 is converted by tissues in the body (liver, brain and gut) into T3.

thyroid gland


If you have been diagnosed with hypothyroidism, this means that your thyroid gland is producing less thyroid hormone than it should. It is a common condition affecting up to 8% of women and 3% of men in the UK and over 10% of people aged over 60.3

symptoms and signs of hypothyroidism

You may not know if you have an underactive thyroid gland. For some people it is a symptomless condition. However, many people report all or some of the following:

  • Trouble getting and keeping warm; feeling sensitive to cold weather or temperatures
  • Being more tired than usual and needing to take naps or sleep more
  • ‘Brain fog’ or poor memory
  • Unexplained weight gain that is difficult to lose
  • Reactions and movement to be slower than normal
  • Patches of dry skin or a loss of skin pigmentation (vitiligo)
  • Thinning hair, or a change in texture (it can become dry and rough)
  • There may be aches, pains and swelling in your arms or legs (and/or muscle weakness)
  • You may develop carpal tunnel syndrome or a puffy face, due to excess fluid retention
  • A deepening of your voice
  • Depression and mood changes
  • Constipation
  • Women can experience heavy periods while men may find themselves struggling to get or maintain an erection
  • A slower heart rate may than usual
  • Increased cholesterol levels
  • A swelling at the front of your neck (also known as a ‘goitre’)

All these symptoms, however, may be caused by a number of different conditions. If you suspect that you may be suffering from thyroid problems, the best way to diagnose this is to ask your doctor for a blood test.

why doesn’t my doctor know about leaky gut?

how do you diagnose hypothyroidism? 

To diagnose a problem with the thyroid gland, blood tests are taken to measure TSH (the signal from the brain) and the levels of thyroid hormone (T4). Hypothyroidism is diagnosed if:

  • TSH is high: This is because the brain knows that thyroid hormone is low and keeps producing more and more signal (TSH), to try and get the thyroid to work
  • Thyroid hormone (T4) is low: The thyroid is not producing enough thyroid hormone

If TSH alone is raised, then it is called subclinical hypothyroidism. A blood test will be repeated in three months to see if the thyroid hormone has dropped. This is a great time to use some natural thyroid supports to prevent it developing into full hypothyroidism.

This is usually the only testing that many hypothyroid patients have ever had, however it is very useful to have additional blood tests, to effectively manage your condition.

Usually, low thyroid hormone is a result of something going wrong with your immune system i.e. it is an autoimmune disease. You can check whether this is the case by having your thyroid antibodies tested, a blood test which will show if your immune system is attacking your thyroid gland. Raised thyroid antibodies can indicate a condition called Hashimoto’s disease, the most common cause of hypothyroidism) and if low may suggest another cause for your thyroid disease.

We can tell how well the body is converting T4 to T3 by measuring T3 levels, as part of an additional blood test. Reverse T3 is very important as it gives us a picture of how healthy our thyroid hormones are. If reverse T3 is inactive, or if there is too much being produced, it blocks the receptors and stops our thyroid hormone working as well as it should. It also prevents T4 converting into T3.

We produce more reverse T3 when the body is under stress, and this means our body can respond less well to thyroid hormones. If your T3 levels are not balanced, you may experience the symptoms of hypothyroidism.

T3 and reverse T3 checks are not part of a standard thyroid test. If you are worried about hypothyroidism, ask your doctor for a T3 and reverse T3 (rT3) blood test, as part of the diagnostic process.

The most common cause of hypothyroidism is an autoimmune condition called Hashimoto’s. Diagnosed with a simple blood test checking for thyroid antibodies as mentioned above (doctors rarely offer to check for this).

Occasionally, low thyroid hormone can be a result of iodine deficiency, surgery, medications, radiation exposure or a problem in your brain (pituitary gland). Sometimes, people are simply born with a thyroid problem. The good news is that there are effective ways to treat hypothyroidism, from medication to nutrition.

how is hypothyroidism usually treated

how is hypothyroidism usually treated?

Once your doctor has diagnosed hypothyroidism, they will prescribe a medication called levothyroxine, which is a synthetic version of the T4 hormone. Your thyroid levels will be tested every six weeks to correctly adjust the dose of levothyroxine. You will then need regular blood tests to monitor your dosage.

It’s important to take thyroid hormone on an empty stomach, as meals or coffee can lower absorption by up to 40%. Studies have also shown that levothyroxine may work better when taken at night.4

Side effects of levothyroxine can include: fever, flushing, headache, heat intolerance, muscle cramps, muscular weakness, oedema, itching, rash, sweating, weight-loss, chest pain, arrhythmias, diarrhoea, excitability, insomnia, palpitations, fast heart rate, tremor and vomiting.

If you do not feel that your symptoms are well-controlled by your medication, seek further medical advice and consider talking to your doctor about referral to an endocrinologist who is experienced in T3 or natural thyroid glandular prescription. A functional medical practitioner or qualified herbalist can also work with you, to look at natural supports and further testing, if necessary.

Many patients struggle with ongoing symptoms of hypothyroidism, despite an improvement in their blood test T4 and TSH. This is likely due to issues in converting T4 to the active hormone T3, and inadequate testing to comprehensively diagnose and manage the condition.

Dr. Jess strongly suggests having a blood test for thyroid antibodies, T3, rT3, iodine and also vitamin D levels (as this is an important vitamin in autoimmune conditions).  If you have this condition or identify with the symptoms above, you can get this done privately with labs like Medichecks, Genova or Doctors Data.

Many functional medical practitioners begin working on naturally supporting the thyroid gland if you have a TSH >2.5 or more.

other perspectives on hypothyroidism

All our many and varied hormones work together to support the body. This means that hypothyroidism could potentially be a wider symptom of other problems. It is important to look at ways to manage stress (the hormone cortisol is involved in thyroid hormone production) and sex hormone balance, as progesterone plays a role in thyroid hormone production.

The thyroid gland is particularly susceptible to damage by toxins addressed further in our natural supports for hypothyroidism article, something rarely considered in conventional medicine.

Finally, never forget that hypothyroidism is usually an autoimmune disease and therefore to deal with the root causes, working on immune and therefore gut health is critical.

If you want to work with a functional medical practitioner, please click here to find one near you.

stress tips

q&a with dr jess 

You mentioned other thyroid hormones like T1 and T2. What can I do to naturally support these? It seems like all the support is around T3 and T4. 

T1 and T2 are poorly understood, though they seem to have minor roles in the body they may also just be precursors and byproducts of to T3 and T4, we don’t yet know. The number after the ‘T’ is related to the number of iodine’s on the tyrosine forming the thyroid hormone. It is logical that if they do have roles we don’t yet understand their levels will be improved when we work on overall thyroid function and also if taking a natural thyroid glandular, rather than levothyroxine, T1 and T2 would also be included.

Why don’t doctors offer complete and comprehensive thyroid screenings? 

Unfortunately mainstream medicine is often 10-15 years behind the latest ‘evidence’ and therefore some of the more recent research on tests like reverse T3 has not yet filtered through to mainstream practice.

There is likely a cost element to doing more expensive in depth testing and tests are only useful if you are interested in supporting and correcting the results. As conventional medicine mainly supplies levothyroxine a TSH is sufficient. Unfortunately little of our health systems budget goes on lifestyle or nutritional support which would have the most impact on many of the other test results. A functional medicine practitioner can do in depth testing with you and help guide you in the best supports for you.

Will I need to take hypothyroidism medicines for life if I am diagnosed? 

In many cases yes, if your thyroid testing shows an ongoing issue with your thyroid then it is important to take thyroid hormone either in synthetic or natural glandular form to avoid the increased risk of cardiovascular disease or infection. However as a functional medicine practitioner with good lifestyle interventions and nutrition I have seen thyroid tests improve (requiring less support) in many cases and sometimes fully correct and stay stable with no further requirement for thyroid hormone.

 Will hypothyroidism impact other areas of my overall health and wellbeing?

As you can see from the symptoms listed above hypothyroidism can have wide ranging effects in the body, with the main long term risks of cardiovascular complications from high cholesterol and high blood pressure. High cholesterol can also increase the risk of gallstones. Because muscles are weakened and sleep apnoea is more common you can be at greater risk of infection and chest infections. If the thyroid is well controlled on blood testing with thyroxine or thyroid glandulars these risks disappear. It is however, important to work on the root causes underneath remembering this is an autoimmune disease and supporting hormone balance.

 Do people with hypothyroidism struggle to lose weight?

Yes this is a common problem, both before hypothyroidism is diagnosed and often still after treatment with levothyroxine. Optimising the thyroid hormone pathways and looking at T3 and reverse T3 can be helpful as can working on nutritional deficiencies, underlying inflammation and gut health.

What should I do if I think I have hypothyroidism?

Always seek advice from your GP or medical provider in order to make sure hypothyroidism is the right diagnosis and to avoid complications.

Once you have been diagnosed, the best approach will differ from person to person and it’s important to individualise treatment depending on various factors such as your history, age, symptoms and severity of hypothyroidism. To find a functional medicine practitioner who can support diet, nutrition, hormonal balance and gut health and help you consider further hormone testing, nutritional testing and genetic factors click here.

To find an experienced and qualified Traditional Chinese Herbalist, Medical Herbalist or Acupuncturist click on the links.


  1. de Lange P, Cioffi F, Senese R, et al.Nonthyrotoxic Prevention of Diet-Induced Insulin Resistance by 3,5-Diiodo-L-Thyronine in Rats  Diabetes. 2011;60(11):2730-2739. doi:10.2337/db11-0207
  2. Accorroni A, Saponaro F, Zucchi R. Tissue thyroid hormones and thyronamines Heart Fail Rev. 2016 Jul;21(4):373-90. doi: 10.1007/s10741-016-9553-8. PMID: 27115768.
  3. hypothyroidism – General Practice Notebook
  4. Bolk N, Visser TJ, Nijman J, Jongste, RN IJ, Tijssen JGP, Berghout A. Effects of Evening vs Morning Levothyroxine Intake: A Randomized Double-blind Crossover Trial  Arch Intern Med. 2010;170(22):1996–2003. doi:10.1001/archinternmed.2010.436