Thyroid problems

Written by Katherine Nicholls
Katherine Nicholls
Nutritionist Resource Content Team

Last updated 8th April 2024 | Next update due 8th April 2027

Our thyroid gland is essential for the cells in our body to work normally. When there is a problem with the thyroid, it can have a big effect on your health. There are two types of thyroid problems: hypothyroidism (an underactive thyroid) and hyperthyroidism (an overactive thyroid). Here, we’ll look at the symptoms of thyroid problems, what treatment is available and what you may need to consider in terms of nutrition and diet.

What does the thyroid gland do?

The thyroid gland is located at the base of your neck. The gland makes two hormones that get released into the blood - thyroxine (T4) and triiodothyronine (T3). Both of these are necessary for the cells in our body to work normally. 

The hormones influence our cell’s metabolism, essentially regulating the speed at which our cells work. If your thyroid gland becomes overactive and secretes too many hormones, this is known as hyperthyroidism. This causes our cells to work faster than normal and can have a knock-on effect on our organs, leading to increased heart rate and more activity in your intestines. 

If your gland becomes underactive and doesn’t secrete enough hormones, this is known as hypothyroidism. This causes the cells and organs to slow down and thus have the opposite effect of hyperthyroidism.

Hypothyroidism (underactive thyroid)

If your thyroid becomes underactive there are a number of symptoms you may notice including:

These symptoms tend to develop slowly and as they are often similar to other conditions may go undetected. If you suspect your thyroid isn’t working properly, be sure to visit your GP. They will be able to run a thyroid function test and diagnose you. 

Many cases of hypothyroidism are caused by the immune system attacking and damaging the thyroid gland. Damage to the gland can also happen as a result of treatments for an overactive thyroid or thyroid cancer. 

If you are diagnosed with hypothyroidism, you will likely be prescribed daily hormone replacement tablets called levothyroxine. You’ll be given regular blood tests to check your levels and may need to tweak the dosage to get it right for you. Once your hormone levels are back in the healthy range, you’ll usually have blood tests once a year to monitor any changes. 

If you aren’t experiencing symptoms of hypothyroidism, or they are very mild, you may not require treatment. 

Hyperthyroidism (overactive thyroid)

If your thyroid becomes too active, it will release too many hormones into your blood and you may experience the following symptoms:

  • feeling nervous, anxious or irritable
  • difficulty sleeping
  • feeling tired and weak
  • being more sensitive to heat
  • experiencing an irregular or fast heartbeat
  • losing weight

If you’re experiencing these symptoms, be sure to visit your doctor for further testing. If you are diagnosed with hyperthyroidism, you may be referred for further tests to identify the cause. There are several reasons why your thyroid may become overactive, including Graves’ disease, lumps or nodules on the thyroid and certain medications. 

Once diagnosed, your doctor will recommend a treatment plan. The main treatments for an overactive thyroid include medication that stops your thyroid from producing too much of the hormones, radioiodine treatment (this involves radiation being used to reduce your thyroid’s ability to produce the hormones) and surgery to remove some or all of your thyroid. 

Normally you’ll speak to an endocrinologist (a specialist in hormone conditions) who will help you decide which treatment is best for your circumstances. 

Thyroid problems can’t be wished away, and almost always require some specific action in order to protect the body from the effects of over- or under-activity. In some cases, medication as well as nutrition will be required. However, I am delighted to say that it is absolutely possible to tailor your nutrition and lifestyle habits to support your thyroid health. 

- Clare Backhouse, PhD, dipION, mBANT, CNHC in 'Eating for thyroid health'. 

Thyroid diet - what to consider

While there are no specific foods that can treat thyroid problems, it’s helpful to eat a varied and balanced diet. Ensuring you eat a diet rich in fruits and vegetables is ideal, as well as avoiding too much sugar and salt. The British Thyroid Foundation recommend a varied diet with calcium-rich foods and normal vitamin D levels. 

If you have been diagnosed with a thyroid disorder, there are some elements of your diet to consider - these are outlined below. 


If you have been prescribed levothyroxine to treat hypothyroidism, it’s worth knowing that some calcium-rich foods and supplements can interfere with its absorption. The British Thyroid Foundation (BTF) say a gap of four hours between the two should be enough to ensure there’s no significant impact on thyroid hormone levels. 


Soya can interfere with thyroxine absorption, so if you have been prescribed thyroxine you are advised to avoid soya where possible. If you do consume soya, you should wait for as long as possible before taking thyroxine.


Kelp is derived from seaweed and can interfere with thyroid function. Because it’s naturally high in iodine, it is sometimes promoted as a ‘thyroid booster’, however the BTF say it is of no health benefit to those with thyroid disease. 


The thyroid gland needs iodine for normal function, with the current recommended daily amount being 150mcg per day. Usually, we can get this amount by enjoying a varied diet. If you have hypothyroidism, it is advised to avoid too much iodine as it can make the condition worse. Taking iodine can also be harmful if you have hyperthyroidism as it can counter the effects of the medication you’re taking.

For people with a properly functioning thyroid iodine is essential as it is required for the production of thyroxine. It is particularly important in women who are pregnant as it is needed to ensure the development of a baby's brain during pregnancy and early life. People who are taking replacement thyroxine (levothyroxine) however do not have a functioning thyroid to absorb iodine and therefore iodine is not required. For patients being treated for hyperthyroidism, taking an iodine supplement is unnecessary and can worsen the condition.

-Dr Mark Vanderpump, consultant endocrinologist

Iron tablets

Iron tablets can also interfere with the absorption of thyroxine. If you are taking thyroxine, your doctor may advise leaving a two-hour gap between taking thyroxine and iron tablets. Be sure to check your multivitamins too, as some contain iron. 

How a nutritionist can help

If you’re living with a thyroid problem, being aware of what you’re eating and how it affects your health is key. A nutritionist with experience in this area will work with you to tailor a diet that supports thyroid health. 

If you are struggling to manage your weight (something thyroid problems may affect) they can help you look at this too. If you’re advised to take any supplements or make any big changes to the way you eat, be sure to check this with your doctor beforehand. 

Related topics

Search for a nutritionist
Would you like to provide feedback on our content?
Tell us what you think

Please note we are unable to provide any personal advice via this feedback form. If you do require further information or advice, please search for a professional to contact them directly.

You appear to have an ad blocker enabled. This can cause issues with our spam prevention tool. If you experience problems, please try disabling the ad blocker until you have submitted the form.

This site is protected by reCAPTCHA, the Google Privacy Policy and Terms of Service apply.

Find a nutritionist dealing with thyroid problems

All nutrition professionals are verified

All nutrition professionals are verified