Do you have an underactive thyroid?

Around 15 in every 1,000 women in the UK suffer from an underactive thyroid – which can lead to debilitating tiredness, weight gain and depression, if left untreated. Here’s all you need to know about the condition… By Jane Murphy

What is it?

The thyroid gland – located in the neck – produces hormones which controls your body’s metabolism. If you suffer from an underactive thyroid – or hypothyroidism, to use the medical term – it simply means you’re not producing enough of these hormones. The condition can’t be prevented – but, once diagnosed, it can easily be treated.

What are the symptoms?

An underactive thyroid can lead to otherwise unexplained weight gain, extreme tiredness, depression, sensitivity to cold, constipation, muscle weakness, aches and pains, dry skin, brittle nails, thinning hair, memory loss, poor concentration, heavy periods and reduced libido.

These symptoms tend to creep up slowly over a period of time. But it’s also important to remember that these are very general complaints that may also be an indicator of other health conditions, not necessarily an underactive thyroid. If you experience any of the above for a prolonged period, it’s important to consult your GP.

If your GP suspects an underactive thyroid, you will be given a simple blood test to measure your hormone levels. In some cases, you may later be referred to an endocrinologist, who specialises in hormone disorders.

What causes it?

Most cases of underactive thyroid are due to one of two causes: the immune system attacking the thyroid; or a damaged thyroid gland, due to surgery or radioiodine treatment for another condition such as overactive thyroid or thyroid cancer.

Other, less common causes include: congenital hypothyroidism (this is when babies are born with the condition); rare side effects of certain medicines; damage to the pituitary gland; and iodine deficiency.

How is it treated?

An underactive thyroid is treated with hormone-replacement tablets called levothyroxine. You will normally be started on a low dosage, which may gradually be increased, depending on how your body responds – so your doctor will monitor you closely with regular blood tests during the first few months. You should usually start to see a real improvement in your symptoms within four to six months. Once the correct dose has been established, you will just need to have a thyroid function test once a year.

Side effects from levothyroxine are very rare: after all, it is simply replacing a missing hormone that your body should have produced naturally. However, if you suffer from any symptoms such as diarrhoea, vomiting, weight loss, muscle cramps and headaches during the first few months of treatment, it may mean the dosage is too high. So do consult your GP as soon as possible if you experience any of these.

Because an underactive thyroid is almost always a permanent condition, you should expect to take levothyroxine for the rest of your life.

Could self-help techniques make a difference?

If you’ve been diagnosed with an underactive thyroid and are taking medication to correct it, it’s vital that you speak to your GP or endocrinologist before making any changes to your diet or lifestyle.

However, if your thyroid function is just a little sluggish, some experts believe you may be able to improve it by boosting your intake of essential minerals, such as iodine, selenium and zinc. Nutritionist Mary-Lou Harris (http://newyoubootcamp.com) advises: ‘Iodine is the key to a healthy thyroid and efficient metabolism. Thyroid hormone is comprised of three or four iodine molecules, which your body can’t produce on its own. It’s found predominantly in seaweed, saltwater fish and eggs.

Mary-Lou also suggests opting for organic wholegrain breads, flour and pasta. ‘Look for the “no bromine” or “bromine-free” label on commercial baked goods, as bromine is a known inhibitor of thyroid function,’ she advises. ‘And avoid unfermented soy products, such as tofu. Many studies link the isoflavones in soy to depressed thyroid function and autoimmune thyroid disease.’

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).