Newspapers and magazines have recently been carrying items about CFS/ME in which it is suggested that problems with thyroid gland function are quite common in this illness and that even in the presence of perfectly normal thyroid function tests it may be worth trying a course of thyroxine tablets (only available on prescription from your doctor).

The real facts are that although disturbances in the levels of various hormones have been described in the medical literature (eg. low levels of cortisol, growth hormone and oestrogen) there is no evidence to indicate that people with CFS/ME are any more likely to have hypothyroidism/myxoedema (low levels of circulating thyroid hormones) than others of similar age and sex. Consequently, I believe that it is most unwise for anyone with CFS/ME, who is known to have normal thyroid function, to start taking thyroxine tablets. Side-effects from having too much thyroxine in the blood include heart rhythm disturbances (which could be fatal in those with any form of existing heart disease) and an increased risk of developing osteoporosis following long-term use. There is also a risk of permanent disruption to the delicate feedback mechanisms which control output of thyroxine from the thyroid gland. I feel so concerned about this misuse of thyroxine that I have written to the British Medical Journal to say that its use should cease until properly controlled scientific studies are carried out into the possible role of thyroid dysfunction in CFS/ME.

Acknowledgment: Reprinted from Perspectives, September 1997, magazine of the M.E. Association (UK), Stanhope House, High Street, Stanford le Hope, Essex SS17 0HA.

Reprinted from Emerge, Summer 1997.