Conclusion
The diagnosis of mild hypothyroidism, with or without laboratory confirmation, has been a subject of controversy for more than 80
years.
It should be remembered that amongst normal adult individuals, thyroid glands vary in weight from 8-50gms, with no doubt a corresponding
variability in thyroid function.
In his landmark book “Biochemical Individuality”, Roger Williams makes the following statement. “Because
of the difference in enzyme systems and the extent to which different metabolic pathways are utilised in different individuals, it
is not at all unreasonable to conclude that different individuals probably have fundamental needs for quite different levels of the
thyroid hormones”.
It may well be that mild hypothyroidism is so frequently a missed diagnosis because symptoms arise and often precede
the blood changes. The Free T4 level in many people may only reliably reflect a low thyroid activity some time after the thyroid has
become deficient. Furthermore, if the whole endocrine axis is hypofunctioning, there is no guarantee or certainty that the blood TSH
will reflect or respond to a thyroid deficiency.
Proposed criteria for diagnosing mild hypothyroidism when the blood test results are
within the normal ranges.
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Request the Free T4 in addition to the TSH.
A Free T4 level below 15pmol/L may be significant. (Dependent on patient’s age)
The basal temperature can assist the diagnosis, i.e. the axillary temperature checked before rising consistently below 97.8°F (36.5°C).
Temperatures as low as 95.8°F (35°C) are not uncommon
Closely evaluate symptoms, particularly morning lethargy and poor short term memory, both symptoms being usual with mild hypothyroidism.
Assess any unexplained weight loss (under 40 years old) and unexplained weight gain (over 40 years old).
Symptom improvement following treatment as outlined below will serve to endorse the diagnosis of mild hypothyroidism.
A useful and satisfactory protocol could be to establish a diagnosis of mild hypothyroidism based on the above criteria. Subsequently
animal thyroid glandular supplements or low dosage thyroxine would be prescribed and the blood retested 3-4 months later.
Blood testing
is essential to identify progress as the patient’s symptoms do not always improve as the blood improves.
Although I have observed with
many patients that the Free T4 can rise within 4-6 weeks, a follow-up test after 3-4 months allows time for more significant changes.
The priority is to obtain satisfactory symptom relief. This is particularly noticeable in the areas of energy, body weight and basal
temperature. I find that when these improvements are achieved the Free T4 is often raised by between 2-5pmol/L.
The blood Free T4 level
that reflects symptom relief can be used as a useful marker for future testing. It can be assumed that the Free T4 improvement (usually
rising to over 15pmol/L) fairly accurately represents that patient’s normal thyroid activity.
