Doctor's Diary: blood tests can mislead in treatment of vitamin B12 deficiency and hypothyroidism

Blood tests being cheap and reliable are indispensable for a correct diagnosis in many situations. But two of the most commonly performed can be misleading, resulting in people either being treated for a condition they do not have or, conversely, not being treated for one they do. Understandably, this has created much confusion that has recently been clarified.

The first is the not-unusual phenomenon of subclinical hypothyroidism, where one of the tests of the function of the thyroid gland shows it to be underactive – in the absence of any of the usual symptoms of tiredness, sensitivity to cold, constipation poor concentration and so on. Here, expert opinion is predictably conflicted. Some argue this indicates thyroid failure and that those symptoms will develop sooner or later, which is obviously undesirable and best-anticipated by commencing in the lifelong treatment with Thyroxine.

But the contrary view – favouring a policy of “wait-and-see” – has recently been vindicated in a major study from the United States showing that active treatment of subclinical hypothyroidism confers no benefit.

The reverse situation is illustrated by the case of a woman recently described by a group of Italian doctors who had all the signs of vitamin B12 deficiency – fatigue, pins and needles and a shiny red tongue – but, according to her blood test, the amount of the vitamin was plumb normal. Nonetheless, they treated her with B12 injections, resulting in “complete recovery” within a month. This situation, it is suggested, is common. Those who wish to know more should look out Martyn Hooper’s very useful book, What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency (£14.99, Hammersmith Books).

Bored to death

Following his recent stay in hospital, television presenter Jeremy Clarkson was reported last week as saying: “The boredom was so bad I thought of killing myself”. Which might be a bit over the top – but only just.

Boredom is a surprisingly interesting state of mind, an indicator of its remorseless need for stimulation and engagement – which, if not fulfilled, can have a whole series of adverse consequences.

When, as in hospital, it is combined with apprehension and other negative feelings, it is, as one patient described it, “my biggest problem and enemy – despite the many opportunities for distraction provided by the internet”.

For the past few years, creative specialist Elizabeth Burns, working with oncology patients at London’s University College Hospital, has found imaginative methods to combat boredom, minimise symptoms of pain and fatigue and promote recovery. Last year, she launched the splendidly titled Anti-Boredom Campaign to promote research into this neglected but important issue. Any suggestions from those who might have successfully combatted the ennui of their time in hospital would be much appreciated.

Odorous plugs 

Finally, the Cambridge gentleman distressed by a persistent smell of burning plastic that “drives out all other odours” weeks after being exposed to the noxious fumes of a melting wall plug has elicited similar experiences from others. They include the grisly account from a retired policeman of breaking down the door of a flat from which a nasty smell was emanating to find the late owner’s body liquefying in front of an electric fire. “The foul smell remained with me for several weeks,” he writes – attributed, by the police surgeon he consulted, to “the absorption of airborne molecules from the decomposing body onto the skin”.

Alternatively, ENT specialist Richard Doty reports that toxic, irritant gases and solvents can cause inflammation of the sensitive olfactory receptors in the lining of the upper nose. This usually improves with time, though “topical steroids that shrink the inflamed tissues can hasten the recovery of the damaged cells”.

• Email medical questions confidentially to Dr James Le Fanu at drjames@telegraph.co.uk