Do you have an overactive thyroid?

About one in 100 people in the UK suffers from an overactive thyroid – and it’s six times as common in women. Left untreated, it can cause debilitating symptoms such as anxiety, insomnia and even heart failure. Here’s all you need to know…By Jane Murphy

What is it?

The thyroid gland – located in the neck – produces hormones which control your body’s metabolism. If you suffer from an overactive thyroid – or hyperthyroidism, to use the medical term – it simply means you’re producing too much of these hormones.

What are the symptoms?

An overactive thyroid can lead to a wide range of symptoms, including extreme weight loss, anxiety, mood swings, hyperactivity, insomnia, constant tiredness, muscle weakness, an enlarged thyroid gland (goitre), diarrhoea, excessive sweating, hair loss, irregular and/or very light periods, loss of libido and fertility problems. It’s important to consult your GP if you experience any of the above.

Left untreated for a long period of time, an overactive thyroid may also significantly increase your risk of heart failure and cause vision problems.

What causes it?

The most common cause of an overactive thyroid is an autoimmune condition called Graves’ disease. This happens when the immune system mistakes the thyroid gland for toxins, and attacks it – leading to an overproduction of hormones.

Another possible cause is nodular thyroid disease, which occurs when benign lumps or nodules form in the thyroid gland – again leading to an excess of hormones. Finally, an excess of iodine in medicines or supplements may also be to blame: iodine triggers the production of thyroid hormones.

How is it treated?

An overactive thyroid is diagnosed via a simple blood test that can normally be carried out in your GP’s surgery. You may then be referred for further tests – such as an isotope thyroid scan – to determine the underlying cause. This involves swallowing a very small amount of radioactive substance in capsule or liquid form. A scan then measures how much of the isotope has been absorbed by your thyroid gland, thus highlighting any overactive areas.

Once the condition is diagnosed, your GP will normally refer you to an endocrinologist (hormone specialist) to decide on the best course of treatment.

You may be prescribed anti-thyroid medication – such as carbimazole and methimazole – to slow down hormone production. It’s usual to start off on a fairly high dosage, which can gradually be reduced as the condition comes under control. It should take around four to eight weeks before you’ll notice an improvement – and you’ll need regular blood tests to monitor your progress. Side effects can include an itchy rash, joint pain and fever – although these tend to subside once your body gets used to the medication.

Your doctor may also temporarily prescribe beta-blockers to help manage symptoms until your hormone levels have settled.

Another non-surgical option is radioiodine treatment – a very low dose of radiotherapy, used to shrink the thyroid gland. It’s taken in liquid or capsule form. Most people only require one treatment – but a follow-up may be given after six months to a year.

Finally, if your condition is severe, your specialist may recommend surgery to remove all or part of the thyroid gland. You will then need to take hormone-replacement medication, known as levothyroxine, for the rest of your life to compensate. This has no side effects.

Could self-help techniques make a difference?

If you’re being treated for an overactive thyroid, you should speak to your GP or endocrinologist before making any major changes to your diet or lifestyle.

However, as the treatment starts to take effect, you may find you start to put on weight: this is only natural as unexplained or unexpected weight loss is one of the main symptoms of an overactive thyroid. If you’re concerned about becoming overweight, it makes sense to embark on a healthy eating and exercise regime that you’ll be able to sustain long-term.

Nutritionist Mary-Lou Harris (http://newyoubootcamp.com) also has this advice: ‘There are a few dietary choices you can make to minimise your potential for thyroid dysfunction. Opt for organic food as often as possible – and wash all produce thoroughly to minimise pesticide exposure. Eat plenty of mineral-rich salt-water and oily fish. And opt for organic bromine-free whole-grain breads, flour and pasta: bromine can inhibit thyroid function.’

Want more dietary advice? Your GP may be able to refer you to a nutritionist – or you can find a qualified local professional via the British Association for Applied Nutrition & Nutritional Therapy (www.bant.org.uk).