Hypothyroidism develops when the thyroid gland can’t produce enough thyroid hormone (either T3 or T4). This causes TSH (thyroid stimulating hormone) to rise. TSH is produced from the pituitary gland. We can easily measure these hormones and then correct the hormone deficiency with synthetic thyroid hormone (levothyroxine).

So treating hypothyroidism should be simple.

Sadly this isn’t so.

In reality many patients with hypothyroidism don’t get treated well.

But why should that be?

Too Much Reliance on One or Two Tests

       The symptoms of hypothyroidism include fatigue, feeling cold much of the time, dry skin and hair, cold hands and feet, brittle nails, low libido, constipation, turning red with exercise and weight gain. The fatigue is typically better in the morning. This disease is thought to affect one in ten of us and is commoner in women and as we get older.

        None of these symptoms are specific but if you have a few of them then you could well be hypothyroid even if some of the tests come back normal.

Any one of the following tests could confirm hypothyroidism with the symptoms mentioned above: a raised TSH, a low T4, a low T3 or having thyroid antibodies.

The problem is that some tests are done more than other. The TSH is done most of the time, the T4 sometimes, the T3 less often and thyroid antibodies quite rarely. So you can see how the diagnosis can be missed.

The TSH Test

       Unfortunately many doctors think hypothyroidism has been excluded if the TSH is normal. It hasn’t.

        Most doctors rely far too much on the TSH test. (Dr Kenneth Blanchard, author of the Functional Approach to Hypothyroidism claims reliance on TSH is the biggest single medical error of modern times). 

The most common mistake I see is that often the only test done both to investigate and to monitor hypothyroidism is the TSH. This means many patients with borderline hypothyroidism get missed or undertreated.

The Tests get Misinterpreted

        Another problem is interpretation of the test. In the UK the TSH is considered to be raised if it is above 5 (in the USA it is above 3). However some specialists believe a trial of thyroid hormones is warranted if the TSH is above 4 (see Thyroid Power).

        Some people have a problem converting T4 to T3. (T4 is the major hormone but T3 is the active form). Their T4 level will be normal but their T3 will (usually) be low. However testing T3 can be unreliable as it is short-acting hormone and levels vary throughout the day.

Treatment is Highly Individual

        Some patients do very well with levothyroxine (synthetic T4 hormone). This is usually gradually increased until the thyroid tests return to normal. Ideally the tests should show T4 in the upper range of normal (normal range: 12 -24 pmol/l) and TSH in the lower range of normal. However some people only feel better when the T4 is slightly above normal and the TSH is below normal (this makes doctors uneasy).

        But many don’t feel well even when the tests return to normal. Why? Sometimes the levothyroxine is not high enough; it may just need increasing until wellbeing returns. However there is a fine line between too little and too much thyroid hormone and if it is pushed too high the likely symptoms are like someone who has had too much coffee: the person feels wired with twitching muscles, feeling too hot, palpitations, poor sleep. How the patient feels is nearly always a better guide than the lab results.

        Some people need T3 to feel well. Liothyronine (Tertroxin) is synthetic T3. Unlike levothyroxine is needs to be given several times daily (3-5 times). Some people only get better with T3 alone, (see Paul Robinson’s book and website: https://paulrobinsonthyroid.com/about/. You can see it’s getting a bit complicated. But it can be sorted out. What is needed here is some flexibility and some experimentation to find what works best for each individual patient.

        A few people do best with natural thyroid preparations such as Armour thyroid. These are what were used in the past. Presently these are prescribable but as an unlicensed medicine. This means some doctors may feel uncomfortable prescribing them.

How to Take Thyroid Hormones

        Levothyroxine is usually taken daily about half an hour before breakfast. However Dr Blanchard finds taking it with meals works better and uses it twice daily with the last dose after the evening meal.

An Additional Thyroid Test

        Dr Barnes developed a simple and accurate method of detecting hypothyroidism. This involves taking the temperature under the armpit first thing in the morning after waking. Leave the thermometer in place for 10 minutes. Normal temperature should be between 97.8 and 98.2F (36.6 and 36.8C). A reading below 97.3 suggests hypothyroidism. Do it on several different days. For menstruating women the temperature varies through the cycle so take the temperature on the 2nd or 3rd day of the period.

Although a basal thermometer (used for detecting ovulation) is best it is not essential. Mercury thermometers are more accurate than digital. It is also possible to take the temperature in the mouth but the readings are 0.5 -1.0 F higher. Leave the thermometer in the mouth for 5 minutes. A reading below 97.8 F (in the mouth) would suggest hypothyroidism. Take on at least 3 days


        A common problem is poor conversion of the major hormone T4 into its active form T3. This step needs selenium as a cofactor (normal dose 200mcg daily). It also requires zinc (use 15mg daily). Supplying these nutrients can be important. However cortisone (from too much stress) can also reduce conversion of T4 to T3.

Thyroid hormones are made from tyrosine and iodine. Tyrosine is rarely deficient.  However there has been some debate about iodine. In the past iodine has proved an effective treatment for hyperthyroidism (too much thyroid hormone) – see iodine leaflet – but there is some concern it could increase auto-immune reactions in hypothyroidism.

 However iodine can also help. It can displace other halogens which would be beneficial so the jury is out. Halogens include fluorides (toothpaste, non-stick teflon pans, many drugs such as fluoxetine), chlorine (tap water, swimming pools and chlorinated chemicals) and bromides (flame retardants, some breads, personal care products). Levels of iodine can be tested in labs like Biolab but not on the NHS.

        Vitamin A is needed for thyroid receptors to work normally.

Why is this Disease so Common?

        The answer is firstly endocrine disrupting chemicals (gender-benders) which abound in the modern world and secondly an increase in halogens in the environment (chorine, fluoride and bromide) which compete with iodine.

Gender-benders are found in many products today but notably in plastics, particularly when heated, and in pesticides.


        Hypothyroidism is thought to be an auto-immune disease. Exactly why this happens isn’t fully understood but what we do know is chemicals can trigger auto-immunity so keep exposure low. We also know Vitamin D helps auto-immune disease. Professor Coimbra has found there is often vitamin D resistance in auto-immune disease and large doses may be needed. Fortunately Vitamin D is very safe. Dr Cannell of the Vitamin D Council has said there has never been a case of Vitamin D toxicity found anywhere in the world for those taking 10,000 IU daily even long-term (this is the sort of dose you would get when sunbathing).  I suspect most patients with auto-immune disease need Vitamin D in the 5000-10,000 IU daily range with some needing much more (see leaflets on Vitamin D and MS pioneers).    


       Good management of hypothyroidism needs a flexible approach and a doctor who regards the patient’s symptoms as being as important as the lab tests.