Additionally to my attempts regarding therapy, I've tried to make a corresponding document for the beginning of diagnosis and treatment. Comments are invited as to hether this provides anyhing useful patients can use.
To the doctor
You and I are meeting to discuss my health problem that I suspect (know) is associated with hypothyroidism. I’m sure we both want to come to a conclusion and treatment that best suits my particular state of health. Therefore before we start, I’d like to put in front of you the ideas and concepts that modern thinking on thyroid function has developed. At the moment, TSH alone is used initially to detect the onset of hypothyroidism. That this test is highly sensitive is not denied, but the interpretation of the test is highly controversial. An important part of this is a decision when, and at what TSH level, therapy by oral thyroid hormone is indicated. In this regard I put the following points to you:
1)The reference range for healthy subjects is generally accepted at 0.5-4 mIU/L. However unlike the symmetrical distribution of values for free thyroxine (FT4) and free triiodothyronine (FT3), the distribution of so-called healthy values for TSH is severely skewed towards the upper end of the scale, so that relatively few patients deemed euthyroid have TSH values above 2.5 mIU/L. TSH values above the top of the reference range up to 10 mIU/L are assigned to subclinical hypothyroid subjects not at the time requiring medication.
2)Individuals maintain health through unique combinations of TSH, FT4 and FT3 applicable only to them. But we do not know what these are, because they have never been measured in health. Therefore, when thyroid disease strikes, it usually does so surreptitiously with only a gradual progressive change to overt hypothyroidism requiring treatment. Because of my individual makeup of thyroid hormones, the point at which indications of a thyroid under strain, but not yet obviously compromised, move to an overt state requiring treatment will be unique to me. However as I said, the start point from health is not known. Therefore diagnosis by “shoehorning” TSH values into categories defined by ranges is not correct. It assumes that everyone will respond equivalently within that range, and that decisions to treat or not can be made purely on statistical, rather than on personal, grounds
3)Diagnosing purely by TSH has to take account of a) my particular makeup as regards thyroid function and b) the symptoms I am displaying:
4)hair loss/limpness, loss of outer part of eyebrows, thickening facial skin, feeling cold, sluggish- THESE ARE JUST EXAMPLES –USE YOUR OWN HERE.
5)A TSH above the reference range but below 10 mIU/L therefore can have many meanings. For some individuals, given obvious symptoms of hypothyroidism, it can strongly indicate the need for treatment. For others with exactly the same value, it may not require treatment at present. However the magic number of 10 mIU/L should not be used as a decision point as to whether to treat or not. There cannot be a hard and fast cutoff point for treatment given patient individuality.
6)Are there any useful blood test pointers that can aid in deciding whether to treat or not that are independent of thyroid function tests? One useful test is blood cholesterol and triglycerides. If hypothyroidism is significant, then these will be raised. On treatment with thyroxine, the levels should fall back to lower values if the treatment is appropriate. Thyroid antibody tests should also deermine whether or not I have autoimmune thyroiditis.
7)I realise that deciding the point when and how to treat hypothyroidism is a difficult area, but decisions based on hard dividing lines cannot be the best way forward given patient individuality. The patient’s presentation is at least as important as biochemical numbers. The recently defined category of subclinical hypothyroidism (i.e. not requiring treatment) has been a retrograde step in diagnosis, as it has consigned individuality in disease progress into a statistically defined mass-based decision
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8)It may possibly be that I display hypothyroid symptoms, when TSH is still within its reference range. In which case, FT4 should be measured to see if it is very low within this range or even below. If this turns out to be the case, it may be that I am suffering from central hypothyroidism (pituitary insufficiency rather than thyroid disease).
9) If in the event, treatment with T4 is indicated, 50 ug should be a starter doses (omit this if over 65 years). When treatment is begun, FT3 should be used as a determinant of successful treatment, realising that neither TSH nor FT4 are adequate in this regard.
10) I hope by combining presentation with biochemical measurements in a considered and personal way, treatment can be begun in a timely way. A problem with delaying treatment is that irreversible changes in the thyroid axis can occur which will be difficult to reverse in the future. This is another dilemma whose implications we should discuss together.