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Who is most at risk of an underactive thyroid?

Who is most at risk of an underactive thyroid?

The thyroid gland, a small butterfly-shaped gland in the front of the neck, is responsible for producing thyroid hormones which play important roles in many of the body's key functions.  Hypothyroidism - more commonly known as having an underactive thyroid - occurs when your thyroid gland does not produce enough hormones. These hormones control the way your body uses energy and affects all our cells and organs. Without enough thyroid hormone many of your body’s functions slow down.

Understanding how common hypothyroidism is, who is most at risk, and the signs to watch for is key to protecting your thyroid health. At-home thyroid tests now make it easier than ever to check your levels and take practical steps if you are concerned.

How common is hypothyroidism?

In the UK, 15 in every 1000 women and 1 in every 1000 men have an underactive thyroid. However, research suggests that many more people may have mild or borderline thyroid issues without realising, as symptoms like daily tiredness often overlap with other conditions. Mild cases can remain undiagnosed for years.

Who is most at risk of developing an underactive thyroid?

Women are much more likely to develop hypothyroidism than men.  Your chances of developing the condition also increase with age,  as cases are much more common in people over 60 years old.

There are other factors too that can place you at a higher risk, for example if:

  • You have a family history of hypothyroidism or other autoimmune disease
  • You have taken anti-thyroid medications or have been treated with radioactive iodine
  • You have had thyroid surgery
  • Your upper chest or neck area has been exposed to radiation
  • You were pregnant or had a baby within the last six months

Your thyroid is also more likely to be underactive if you have other health problems including:

  • Coeliac disease
  • Type 1 diabetes
  • Rheumatoid arthritis
  • Pernicious anaemia
  • Lupus

Recent guidance highlights that menopause can affect thyroid health. Whilst menopause itself does not cause thyroid disease, the hormonal shifts, increased autoimmune activity, and overlapping symptoms that some women experience may increase the likelihood of thyroid problems, or make them more noticeable at this stage of life. If you experience fatigue, weight changes, or mood disturbances during menopause, it may be worthwhile considering a thyroid check.

Even if you have several of these risk factors, this does not mean that you will necessarily go on to develop an underactive thyroid. Nor does it mean that if you have none of them, the condition won’t affect you. It simply means that your risk of developing it is greater.

What are the main symptoms of an underactive thyroid?

Because hypothyroidism develops slowly, you may not notice symptoms of the disease for months or even years. People often dismiss the early signs as part of stress, ageing, or busy lifestyles. Being aware of these common hypothyroidism symptoms can help you spot issues earlier and seek testing:

  • Fatigue
  • Weakness
  • Weight gain
  • Dry, coarse hair
  • Dry, rough, pale skin
  • Hair loss
  • Intolerance to the cold
  • Muscle cramps and aches
  • Constipation
  • Depression
  • Irritability
  • Memory loss
  • Abnormal menstrual cycles
  • Reduced libido

Lifestyle and dietary considerations

The cornerstone of hypothyroidism treatment is levothyroxine replacement therapy. Levothyroxine is a synthetic form of the thyroid hormone thyroxine which restores normal hormone levels. Whilst medication is essential, it’s important to note that everyday lifestyle choices can also influence how well treatment works and how you feel day to day. In other words, think of healthy habits as creating the best environment for your thyroid and overall wellbeing.

Nutrition matters, and there are some good habits we can adopt to support our thyroid function:

  • The thyroid needs small amounts of iodine to make hormones. Most people get enough through everyday foods like dairy, eggs, and fish, so extra supplements are rarely needed. In fact, ingesting too much iodine, through foods like seaweed snacks or kelp tablets – for example, can actually make thyroid problems worse.
  • Selenium, found in foods such as Brazil nuts, chicken, and wholegrains may support thyroid hormone production. However you only need a small amount, so aim to include it as part of a balanced diet rather than taking high-dose supplements.

We’ve mentioned medication, and the timing of this is also important:

  • Levothyroxine is commonly prescribed to help restore normal hormone levels in the body.
  • But how you take it matters. Calcium (from milk, yoghurt, or supplements) and iron (from red meat, spinach, or tablets) can reduce how well levothyroxine is absorbed. To avoid this, take your thyroid medication on an empty stomach with water, and wait at least four hours before having calcium or iron-rich foods or supplements.

Everyday physical habits are essential to wellbeing, and they play a key role in supporting the thyroid:

  • Regular activity, even a brisk daily walk, can help with the tiredness, weight gain, and low mood that often come with hypothyroidism.
  • Gentle exercise such as yoga or swimming may also ease muscle aches and stiffness.
  • Prioritising good sleep and keeping stress levels down can support overall hormone balance, making it easier to cope with symptoms.

Simple swaps can help too. For example, try replacing processed snacks with fruit and nuts for steady energy, or choosing wholegrain bread instead of white bread to keep digestion regular. These small changes may not “cure” hypothyroidism, but they can make day-to-day life with the condition easier.

How can I tell if I have an underactive thyroid?

If you suspect you might have an issue with your thyroid, you can check by taking one of our thyroid at-home tests.

MyHealthChecked’s Thyroid Stimulating Hormone (TSH) Rapid Self Test is a quick and easy way to screen for hypothyroidism. Since abnormal levels of TSH suggest a disruption of your body’s normal thyroid function, this test will give you a good indication within 10 minutes if your thyroid stimulating hormone (TSH) levels are normal. If they are higher than normal, this suggests you may have an underactive thyroid.

MyHealthChecked’s Thyroid Profile Blood Laboratory Test goes one step further. This self-sample collection kit can also be performed at home, before posting your sample to be analysed at our laboratory. Once it arrives, our experienced scientists will check the levels of both your thyroid stimulating hormone (TSH) and thyroxine (T4) to assess whether you may have either an underactive or overactive thyroid.

Both options allow you to test from home, giving you accessible, private insights into your thyroid health without needing an immediate GP appointment.

Is hypothyroidism serious?

If your test suggests you might have any type of thyroid disorder, you should always seek medical advice. The good news is that hypothyroidism is usually straightforward to treat. With proper treatment, most people with an underactive thyroid can lead a normal, healthy life.

If left untreated, hypothyroidism can lead to complications such as high cholesterol, high blood pressure, fertility issues, and problems during pregnancy. It may also increase the risk of goitre, where the thyroid gland becomes enlarged, leading to swelling at the front of the neck and symptoms such as difficulty swallowing or a hoarse voice.

In summary

Living with an underactive thyroid can be challenging, but understanding the risks, recognising symptoms, and making small lifestyle changes can make a real difference. Eating well, staying active, and paying attention to how your body feels are all part of supporting thyroid health. If you are concerned, MyHealthChecked’s Thyroid Stimulating Hormone (TSH) Rapid Self Test and Thyroid Profile Blood Test provide simple at-home ways to check your hormone levels. These tests give you valuable insights and can guide you on whether to seek further medical advice. With the right awareness and support, most people with hypothyroidism can live well and feel more in control of their health.

Reviewed by Dr Gavin Ralston

References

  1. NHS Scotland. (n.d.). Underactive thyroid (hypothyroidism). https://www.nhsinform.scot/illnesses-and-conditions/glands/underactive-thyroid
  2. National Center for Biotechnology Information. (2017). Insulin resistance. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK519536/
  3. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH. (n.d.). Hypothyroidism. https://www.niddk.nih.gov/health-information/endocrine-diseases/hypothyroidism
  4. EndocrineWeb. (n.d.). Hypothyroidism. https://www.endocrineweb.com/conditions/hypothyroidism
  5. National Institute for Health and Care Excellence (NICE). (2019, updated 2023). Thyroid disease: assessment and management (NG145).https://www.nice.org.uk/guidance/ng145
  6. British Thyroid Foundation. (2022). Hypothyroidism (leaflet).https://www.btf-thyroid.org/hypothyroidism-leaflet
  7. British Thyroid Foundation. (2024). Thyroid & menopause.https://www.btf-thyroid.org/thyroid-menopause
  8. National Institute for Health and Care Excellence (NICE) Clinical Knowledge Summaries. (2024). Hypothyroidism: diagnosis and management.https://cks.nice.org.uk/topics/hypothyroidism/