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What is an overactive thyroid?

20 Aug 2021 • 3 min read


Also known as hyperthyroidism or thyrotoxicosis, an overactive thyroid is a complex issue where the thyroid gland (a small-butterfly shaped gland in the neck) produces too many thyroid hormones.

These thyroid hormones can affect many different bodily functions such as heart rate, metabolism and body temperature – amongst other things.

If your body produces too much of these hormones, it can lead to various unpleasant symptoms and may need treatment.1

What is the difference between an overactive thyroid and an underactive thyroid?

An underactive thyroid is essentially the opposite of what we have explained above, where the thyroid gland doesn’t produce enough of the thyroid hormones to function properly.

This slows down the functions of the body, such as our metabolism, and can therefore sometimes lead to weight gain, tiredness and even depression.2

How does an overactive thyroid make you feel?

An overactive thyroid can make you feel a large range of different things, from changes to your mood, sleep habits, energy levels, heart rate and weight.3

What causes an overactive thyroid?

There are various different factors and conditions that can cause an overactive thyroid. These include:4

  1. Grave’s disease – this is an autoimmune condition where the thyroid is wrongly attacked by the immune system, causing it to become overactive.
  2. Thyroid nodules – these nodules or lumps that can be on the thyroid can also contain thyroid tissues in them, which can lead to the over-production of thyroid hormones.
  3. Certain medication – medications that contain iodine may cause the thyroid to release too many hormones.

What are the symptoms of hyperthyroidism in females?

While both men and women can have an overactive thyroid, this condition is roughly ten times more common in women than in men – and is most commonly developed between the ages of 20 and 40.5

So what are the symptoms of hyperthyroidism in females? Here’s what to look out for more generally:6

  1. Nervousness, anxiety and irritability
  2. Mood swings
  3. Difficulty sleeping
  4. Persistent tiredness and weakness
  5. Sensitivity to heat
  6. Swelling in your neck from an enlarged thyroid gland (goitre)
  7. An irregular and/or unusually fast heart rate (palpitations)
  8. Twitching or trembling
  9. Weight loss

Some symptoms that are specific to females alone are:7,8

  1. Issues with menstrual cycle. Either too much or too little of the thyroid hormones can cause periods to be lighter, heavier or irregular. It may also cause your periods to stop for prolonged periods of time, from several months to years. If your body's immune system is the cause of your thyroid issues, other glands, including your ovaries, may be involved, which can lead to early menopause (before age 40).
  2. Issues getting pregnant. As thyroid issues can cause your menstrual cycle to change, this also means that it could affect ovulation – potentially making it harder to get pregnant.
  3. Can cause issues during pregnancy. Hyperthyroidism if left untreated may cause premature birth, preeclampsia, thyroid storm, fast heart rate in newborns, low birth rate and even miscarriage.

What are the symptoms of hyperthyroidism in males?

So we’ve run through the symptoms of hyperthyroidism in females, but what about how they present themselves in men? Here’s what to be aware of:9,10,11

  1. Erectile dysfunction. There is a strong correlation between hyperthyroidism in men and erectile dysfunction, with studies showing that up to 60% of men with the condition struggle with this.
  2. Gynecomastia. This is where the breasts swell and appear larger than normal.
  3. Decreased libido. When men with hyperthyroidism were studied, they found that the bioavailable testosterone was found to be subnormal with an elevated circulating estradiol (E2) – which can lead to the above symptoms as well as a lower libido.

What are the symptoms of hyperthyroidism in children?

Otherwise known as pediatric hyperthyroidism, children can also develop an overactive thyroid – and it can even be present in newborns. Some of the symptoms of hyperthyroidism in children include:12

  1. Weight loss
  2. Fast or irregular heart rate
  3. Raised blood pressure
  4. Enlarged thyroid gland at the front of the neck, also called a goiter
  5. Tremors
  6. Poor heat tolerance and sweating
  7. Anxiousness and irritability
  8. Hyperactivity or restlessness
  9. Difficulty concentrating
  10. Trouble sleeping
  11. Loose or increased bowel movements (pooping)
  12. Fatigue
  13. For girls: light, infrequent menstrual periods
  14. Increased appetite
  15. Redness, pain or bulging in the eyes
  16. Light sensitivity
  17. Dryness
  18.  Double vision

What happens if you have an overactive thyroid?

If you suspect you have an overactive thyroid, get in touch with your GP for an appointment.

From here, they’ll then ask you about the symptoms you’ve been experiencing, before booking you in for a blood test to try and determine whether you do have an overactive thyroid or not.

If the blood tests show that you do have an overactive thyroid, there’s a chance you’ll be booked in for further tests to identify the cause.

Or, you’ll receive information on how to treat an overactive thyroid so you can make a more informed decision about what you want to do next.

How serious is an overactive thyroid?

In a lot of instances, an overactive thyroid can be treated through medication, radiotherapy or surgery.

However if left untreated or poorly managed, the condition can become very serious.

For example, a thyroid storm where the symptoms flare up in an extreme way can take place, eye issues could develop, and it could lead to pregnancy complications as mentioned earlier in the article.13

How is an overactive thyroid treated?

Generally speaking, an overactive thyroid can be treated – but there can sometimes be complications. The main treatments for an overactive thyroid include:14

  • Overactive thyroid medication. Thioamides medication that stops your thyroid from releasing too many hormones. The most common ones are carbimazole and propylthiouracil and they’re usually taken for one to two months before you notice any benefits.
  • Radioactive iodine treatment. This is a form of radiotherapy that is used to get rid of the cells in the thyroid gland, reducing the amount of hormones it can produce.
  • Surgery. In some instances, the thyroid is surgically removed completely – stopping all the symptoms from coming back, which isn’t necessarily the case with the other treatments.

Natural ways to manage an overactive thyroid

  1. L-carnitine

A natural supplement that may help with managing an overactive thyroid is L-carnitine – a naturally occurring amino acid found in the body.

A 2001 study found that it can sometimes reverse and prevent the symptoms of hyperthyroidism.15,16

  1. Lemon balm

While there is a lack of clinical evidence on the effectiveness of using lemon balm for hyperthyroidism, test-tube studies have shown that it does block the attachment of antibodies to the thyroid cells that cause it.

And it is the flavonoids and phenolic acids that are said to be the reason for this.17

  1. Selenium

A mineral that is found in water, soil and foods, selenium has been shown to be able to help the symptoms of an overactive thyroid.18

  1. Glucomannan

Derived from the root of the konjac plant, glucomannan can be taken in a variety of ways – from capsules to powders and tablets.

One study from 2007 indicates that it could be a safe and easily tolerated therapeutic agent in the treatment of thyrotoxicosis.19

  1. Lavender essential oils

Two common symptoms of hyperthyroidism are anxiety and trouble sleeping, therefore diffusing an essential oil like lavender into the air could help to calm these feelings.

  1. Sugar-free diet

Anecdotal evidence suggests that a sugar-free diet, combined with meditation, may help to calm the nervous system at a cellular level.

Equally, the intake of artificial sweeteners should be monitored as this may have an effect on gut microbiomes and therefore the thyroid.20

  1. Vitamin B

While vitamin B can’t treat hyperthyroid symptoms on their own, it may support feelings of fatigue, dizziness and weakness.21

  1. Probiotics

Another natural way to manage an overactive thyroid is through probiotics.

A recent study highlighted that probiotics have a beneficial effect on thyroid diseases and may have a positive effect on trace elements like selenium, zinc, and copper.22

  1. Gluten-free diet

And finally, another potential way to manage symptoms of an overactive thyroid is through a gluten-free diet.

A recent study came to the conclusion that this could bring beneficial clinical effects to women with autoimmune thyroid disease.23

The final say

Hyperthyroidism is a complex health condition that can affect many different bodily functions.

However, there are various treatments that you can receive from the doctors, alongside more natural ways that may help you to manage some of the unpleasant symptoms.

If you suspect you have an overactive thyroid, please get in contact with your GP to discuss further.

Handpicked content: 6 symptoms of an underactive thyroid

The advice in this article is for information only and should not replace medical care. Please check with your GP or healthcare professional before trying any supplements, treatments or remedies. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle.

Last updated: 20 August 2021



Author: Bhupesh PanchalSenior Regulatory Affairs Associate

Joined Holland & Barrett: Apr 2019

Masters Degree in Toxicology and BSc Hons in Medical Biochemistry

Bhupesh started his career as a Clinical Toxicologist for Public Health England, advising healthcare professionals all around the country on how to manage clinical cases of adverse exposure to supplements, pharmaceuticals, cosmetics, industrial chemicals and agricultural products.

After 7 years in this role and a further year working as a drug safety officer in the pharmaceutical industry, Bhupesh joined Holland & Barrett as a Senior Regulatory Affairs Associate in 2019.

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