Informational Posts

Are Thyroid Patients More Prone to Getting Sick?

Originally published on 19th March 2019
Last updated on 29th January 2024

Does having an underactive thyroid or hypothyroidism reduce your immune function? In other words – do we get sick more easily than others?

Let’s look at why this may be so and what we can do to try and prevent getting sick so often.

Rachel Unwell Hospital

The Thyroid Patient, The Sickly Friend.

I’ve definitely had my fair share of being sickly – catching all and any bugs, colds and viruses going around – and this was at its worse when my autoimmune hypothyroidism (Hashimoto’s) was first triggered.

In fact, I was admitted to the intensive care unit with pneumonia at just seventeen-years-old, when I should have been the perfect image of health, youth and vitality, but my body just couldn’t fight it off and so I ended up in intensive care on breathing support.

I wasn’t diagnosed with Hashimoto’s and hypothyroidism until four years after this bout of extreme sickness, but the pneumonia was a marker in the downward spiral. From seventeen-years-old, I caught countless colds, bugs and viruses, seemingly one after another and it quickly became  an ‘in joke’ that I was ‘Rachel, the sickly friend’ or ‘Rachel, the sickly one in the office’.

Sound familiar?

Separating Thyroid Symptoms From Short Term Illness

Rachel looking tired and sleepy on a sofa

It’s certainly common to hear other thyroid patients complaining of always feeling as if they’re unwell, and, whilst we do need to bear in mind that hypothyroidism itself causes symptoms similar to that of a cold or the flu – aches and pains, heavy fatigue, trouble sleeping, a hoarse voice – separating the chronic health condition with a short term illness is important.

Many of us experience thyroid flare days, where we feel convinced we are coming down with a virus or flu and then find we’re over it a day later. These are often flares.

I have also written about what we may experience when catching an illness on top of hypothyroidism before, which you can read here.

So the question remains: Are we more prone to illness?

Overall, yes, we can be more vulnerable to catching illnesses due to our thyroid condition. And this can be down to a mixture of reasons. Let’s explore them below.

Researching Thyroid Information

Vitamin Levels

Many thyroid patients have deficient or low levels of certain vitamins and minerals that are essential for a well-functioning immune system.

These include:

  • Selenium
  • Vitamin D
  • Vitamin K
  • Vitamin A
  • Vitamin E
  • and Zinc.

Many of us are even diagnosed with a thyroid condition at the same time as low Iron, B12 or Vitamin D.

Those of us with autoimmune hypothyroidism are at particular risk of low levels of these, most likely due to poor gut health and absorption issues.

Many symptoms of Vitamin A deficiency and hypothyroidism overlap, for example.  This may be due to the fact that both conditions influence and promote the other.

Symptoms of Vitamin A deficiency include:

  • Frequent sickness such as colds or respiratory issues
  • Dry eyes
  • Brittle or dry hair
  • Skin conditions such as acne or dry skin
  • Poor digestion and nutrient absorption
  • Infertility or miscarriage

Without enough Vitamin A, the body may experience immune dysfunction with poor nutrient absorption and digestion. This can then go on to contribute to the development of poor gut health.

Getting enough zinc is also crucial for immune function and has become a popular treatment for the common cold. Some studies have found that zinc lozenges can reduce the duration of a cold by as much as 50% and as soon as I feel a cold coming on, I up my intake which has helped to fight it off much quicker or even stop the cold from progressing past a couple of days. Many of us are low or deficient in zinc.

Vitamin D and K is crucial in activating your immune defences. Scientists have found that without a sufficient intake of Vitamin D, the killer cells of the immune system (T cells) are not able to react to and fight off serious infections in the body. A research team found that T cells first search for vitamin D in order to activate and if they cannot find enough of it will not complete the activation process. [1]

Vitamin E supports the immune system so that it can fight off any invading bacteria and viruses.

Good nutrition can deliver all of these important vitamins, improve your ability to fend off colds, flu and other illnesses and support the immune system among other bodily functions. To read about supplements, please see here.

Foods naturally high in Vitamin C which can also help, including Kiwi, Pineapple, Mango, Strawberries etc. Of course, some thyroid patients also supplement this.


Sleep issues are another symptom of thyroid disease, even though many of us live with intense, heavy fatigue, we often find it difficult to fall asleep and stay asleep at night. Does the phrase ‘tired but wired‘ resonate with you?

Wherever this is an issue, adrenal function should be checked to consider a cortisol issue disturbing your sleep patterns (very common with hypothyroidism). Not getting enough good quality sleep can cause the body to be under stress as it’s not having enough time to rest, recharge and function correctly – and this is the same for the immune system.

The adrenal glands dysfunctioning can cause a whole host of symptoms such as craving sweet or salty foods in excess, anxiety, intense fatigue plus many more, but abnormal cortisol levels can also affect your immune system’s functionality, so I always suggest checking this out with a 24-hour 4-point saliva test, as it often comes hand in hand with low thyroid and vitamin levels. A UK one can be found here.

Other ways to promote good sleep include sticking to a routine of getting up and going bed at the same time everyday, turning off electronics a couple of hours before bed, taking a bath which can also use Epsom salts, Magnesium supplementation and more.

Feeling Cold (and The Winter Months)

Something else to consider is that hypothyroidism patients also frequently experience cold sensitivity, where they feel the cold much more than others.

This can further contribute to reduced immune function as keeping warm is essential.

As well as ensuring that your thyroid levels are optimal, which should help to correct your metabolism and thus produce more heat for your body, you can make wearing extra layers in the cooler months of the year a priority also, to support your immune system and keep it as active as possible.

There are thermogenic foods that are named as such as they create heat when they’re converted in to energy. Common ones include chillies, pepper, mustard, coconut oil and even avocado.

Just as I covered in Why Do We Often Need Less Thyroid Medication in Warmer Months?, many of us also need more thyroid medication in colder months. Not a lot, but a slight medication increase can help our bodies stay warm and function without pesky hypothyroid symptoms returning or worsening in the colder months. Of course, don’t make this adjustment on your own but rather speak to your doctor. You’d likely benefit from a retesting of a full thyroid panel in winter.

It’s worth knowing that you can order full thyroid panels yourself from online laboratories too. Find a UK lab here and a worldwide lab here.

You may also want to consider whether the flu jab is suitable to you, as it could prevent another illness.

Gut Health

Most of your immune system exists in your gut, so promoting good gut health can also help. Probiotics, bone broths and digestive enzymes may help and do indeed help me when I feel under the weather.

Note: I always recommend consulting your doctor, pharmacist, a medical professional etc. before making any changes to your health regimen. It can be dangerous if you take supplements and already have high/sufficient levels. Of course, all pregnant women should be especially careful and consult a medical professional.

Are We Really Prone To More Illness?

So, as you can see, there may be multiple reasons why we’re more prone to catching all illnesses going around.

However there is also some evidence to suggest that people with autoimmune conditions such as autoimmune hypothyroidism (Hashimoto’s), are that way because their immune system is better equipped to combat dangerous infections, enabling them to live longer. [2]

Research found that individuals with higher levels of antibodies were likely to live longer. Interesting, huh?

What do you think?

Do you find that you’re sick more often than other people? Have you explored whether any of the above suggestions could be the reason why?

You can click on the hyperlinks in the above post to learn more and see references to information given.




About Author

Rachel Hill is the highly ranked and multi-award winning thyroid patient advocate, writer, speaker and author behind The Invisible Hypothyroidism. Her thyroid advocacy work includes writing articles, authoring books, producing her Thyroid Family email newsletters and speaking on podcasts and at events about the many aspects thyroid disease affects and how to overcome these. She is well-recognised as a crucial and influential contributor to the thyroid community and has a large social media presence. Her bestselling books include "Be Your Own Thyroid Advocate" and "You, Me and Hypothyroidism".


  • Dawn
    November 5, 2021 at 12:51 pm

    I recently got out of hospital after a bout of pneumonia, i honestly feel ive never recovered (4 weeks ago) havent returned to wrk yet, feel freezing and just want to sleep, im on my 3rd bad chesty cough in 2 months 🙁 how do i get my GP to listen and check all these things? I know im not ok but not sure where to start myself tbh x

    • An
      June 30, 2023 at 3:41 am

      My daughteris 7 years old and she always catch bugs at school. For some reason she is sick every other week and has missed a lot of school days. She probably have catch all the bugs at school. One day, she was super sick that I have to take her to emergency and they have to test her blood test so I randomly requested to also check her thyroid too. Since her baby brother has congenital hypothyroidism. Surprisingly her tsh level was at 7.5 but the doctor told me it’s high maybe because she is just sick. Normally thyroid works harder when body is sick. Anyway, my daughter has all the classic signs. So I don’t if I have to wait another month to check again and see if her tsh is settled after getting better.


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