Dr Tim Cheetham answers questions from parents and children about thyroid disorders. Dr Cheetham is Consultant Paediatric Endocrinologist (a hormone specialist) working at the Royal Victoria Infirmary, Newcastle upon Tyne.

If you have a question for Dr Cheetham about thyroid disorder in children, email him at drtim@btf-thyroid.org

Q: Why do I have to take thyroid medicine? None of my friends take medicine. I hate it. It's not fair.

A: I quite agree - it isn’t fair. Treating thyroid problems is the lesser of two evils, however. In other words it is better to take the tablets regularly and have your thyroid checked in clinic every few months than to feel poorly and have problems with bones, heart, weight, concentration span etc because of too much or too little thyroid hormone in the body.

Q: I don't want my child to be on ‘drugs’ all their life. Isn't there an alternative?

A: The beauty of thyroid medicine is that it is ‘replacement’ for thyroid hormone - putting back what nature isn’t making. Too much or too little of any hormone isn’t good for you. The aim with thyroid hormone replacement is to get the amount in the body just right.

Q: The doctor has prescribed 50mcg of levothyroxine one day and 75mcg the next. It is supposed to balance out, but even the class teacher at school can tell which dose my child is on that day because of their behaviour. What can I do?

A: Because levothyroxine has a so-called ‘long half-life’ (when you take a dose it stays in the body a long time) many doctors will say that alternating the dose shouldn’t make a big difference. They will say that if the daily dose was critical and can affect the way you feel so much then why do so many people (that includes adults!) struggle to take the medicine regularly? If you believe there is a link then what some people do in his situation is try halving the tablet with a tablet cutter and see if taking 62.5mcg daily makes any difference.

Q: The school has been complaining about my child's behaviour ever since the doctor raised the dose.

A: Consider having your child’s the thyroid function tests checked again! Speak to your doctor who will usually be very happy to arrange for the bloods to be checked. Are there any other reasons why their behaviour might have changed?

Q: My daughter has been diagnosed with Graves’ disease and our doctor has recommended either surgery or radioactive iodine treatment. Surgery sounds scary to me and we don't want to be left with a nasty scar, but radioactive iodine sounds even worse. What should we do for the best?

A: Good question. In North America doctors are fans of radioactive iodine (RAI) whilst in Europe there are still many people who think that surgery is best. That says it all - both have advantages and disadvantages and it is important to speak to experts who can talk in more detail about these issues. It will still be a matter of personal choice though!

Perhaps the key things to think about are that thyroid surgery is safe when conducted by skilled and experienced surgeons. There is a scar but this usually fades quite dramatically with time. On the other hand, recent work has suggested that treating young people with RAI is very safe and doesn’t cause problems such as cancer in young people.

Q: The paediatrician says an annual blood test is enough, but I am worried and think it ought to be more often.

A: Blood tests are needed more often in very young children or in people who have just been diagnosed. Discuss your worries with your doctor who will probably be very willing to arrange for more frequent testing.

Q: This is something l would like to know. l have been on carbimazole for 7 years. l know after long periods it could affect your bone marrow. Can you tell me what this means? Can it make your bones a little bit weaker as l have just fractured my arm again so that is now both arms in 18 months. Thank you.

A: Occasionally carbimazole can suppress the bone marrow (the central bit of bone) and stop it from making the white blood cells normally (the white cells in the blood stream are responsible for fighting infection). This can still happen many years after starting carbimazole and is one reason why people on this medicine should always have their white count checked when they have a sore throat – even after 7 years!

Carbimazole should not, however, make your bones weak to a point where they break more easily and so I suspect that the breaks are nothing to do with the medicine. Presumably it was a significant bang to the arm that resulted in it breaking and not a gentle tap!