Ways of treating an overactive thyroid

Here we take a look at the treatment available for an overactive thyroid and any side effects you may encounter

What is an overactive thyroid?

Hyperthyroidism or overactive thyroid is a condition where the thyroid gland produces excessive amounts of thyroid hormones.  Over production of these hormones can ramp up the body’s metabolism which in turn can result in symptoms such as sudden weight loss, tiredness, rapid or irregular heartbeat, excessive sweating and irritability.

Carbimazole and propylthiouracil

Carbimazole or propylthiouracil are both medicines that are prescribed to treat an overactive thyroid and they work by reducing the amount of thyroxine hormone naturally produced.

A high dose is usually given in the first instance and it takes several weeks for the levels of excess thyroid hormones in the body to start to decrease.

After prescribing carbimazole or propylthiouracil for the first time your doctor will give you a blood test at around 4 to 6 weeks to check your thyroid levels and will then make any adjustments to the dose if needed.  Your doctor will continue to monitor your thyroid levels with blood tests every 3 to 6 months until you fall within the normal range.

Are there any side effects of the medication?

Some people have reported feeling sick, having an upset stomach, headaches, aching joints and an itchy rash after taking carbimazole or propylthiouracil but these symptoms will usually stop as your body adjust to the medication – generally at around 8 weeks.

Occasionally the medication can result in a lowering of white blood cell levels which can lead to the risk of infection such as a sore throat, mouth ulcers, high temperature or unexplained bruising or bleeding – but this is rare.

If, however, you do experience any of these symptoms then it is advisable to arrange for a blood test with your doctor to get it checked out.

For some, taking carbimazole or propylthiouracil is enough to return the overactive thyroid to normal, however, for others who don’t respond to medication alternative treatments may be considered – such as radioiodine or thyroid surgery.

The radioiodine therapy option

Radiation can be used to reduce the amount of hormone produced by the thyroid by damaging or destroying its tissue – this is known as radioiodine therapy.

Radioiodine therapy is highly effective and can usually treat an overactive thyroid in a single dose.  It is given either as a capsule or a drink.

It is not suitable, however, if you are pregnant or breastfeeding, if you are vomiting or incontinent or suffer from eye problems as a result of your condition.

Click here if you would like to know more about radioiodine therapy.

The surgery option

Surgery to have part or all of the thyroid gland removed may be considered if your thyroid gland is severely swollen (goitre), if you suffer severe eye problems due to the condition, if other treatments have failed or if your symptoms return following treatment.

Medication such as levothyroxine is prescribed if all of the thyroid is removed after surgery.  This replaces the missing thyroxine hormone and will have to be taken for the rest of your life.

There are many things to consider when you have an overactive thyroid so if you feel you would like to see another endocrinologist for a second opinion your GP should be able to arrange this for you.

Useful resources

Overactive thyroid (hyperthyroidism) – NHS factsheet

The British Thyroid Association

Thyroid UK

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