Life insurance and overactive or underactive thyroid

6 min Read Published: 30 Nov 2020

Thyroid Conditions Life InsuranceAn overactive or underactive thyroid can be a slow and tricky condition to diagnose.  The symptoms are often subtle and can take a long period of investigation before they are linked back to your levels of thyroid-stimulating hormones. Often, sufferers will worry about the wide spectrum of conditions that the symptoms may be linked to and given that the condition in of itself can cause low feelings, this is understandable.

If you're someone with this condition and want to understand how it would impact an application for life. critical illness or income protection insurance, you'll find this article useful. We have looked at the conditions and how they are assessed by insurers as well as what outcomes you can expect. You'll even find some information on how to get £50 cashback when you take a policy.

What are the most common thyroid conditions?

The thyroid is a butterfly-shaped gland in your neck that sits just in front of your windpipe or trachea. The function of this gland is to produce hormones that regulate the body's metabolism which is your bodies function that turns food into energy. Generally, a change in the way that this gland is working can lead to producing too little or too much of the hormones that the body needs. These hormones regulate body functions such as heart rate, digestion, weight, energy levels and mood.

The most commonly associated conditions are Hypothyroidism, also known as an Underactive Thyroid and Hyperthyroidism which is an Overactive Thyroid. It can affect both men and women, however, is more prevalent in women and may be found at birth too, although this is rare.  Over or underactivity of the thyroid gland causes the pituitary gland to respond as it measures the hormone output from the thyroid gland.

Another condition associated with the thyroid gland is Thyroid Cancer but we will not look at that within this article. If you would like to read more about how cancer affects a life insurance application, you can read more about it in our article 'Can I get life insurance if I've had Cancer?'

What causes an overactive thyroid?

  • Graves Disease is a condition that can cause an overactive thyroid and 3 out of 4 people who suffer with Graves Disease experience an overactive thyroid.
  • An overactive thyroid can also be caused by lumps or nodules on the gland that produce excess hormones.
  • Medication that is used to treat some heart irregularities may also cause the thyroid gland to become overactive.

What causes an underactive thyroid?

  • Hashimoto's Disease is a known cause of an underactive thyroid and is referred to as Hashimoto's Thyroiditis. It's often linked to inherited conditions and is sometimes observed alongside other autoimmune illnesses like Type I Diabetes or Vitiligo.
  • The treatment used for an overactive thyroid or thyroid cancer can also cause an underactive thyroid by inhibiting too much hormone production.
  • There are other less common causes of an underactive thyroid including congenital hypothyroidism, viral infections or it can be caused by medications being taken for other reasons.

What information do I need to apply for life insurance if I have an under or overactive thyroid?

When applying for life, critical illness or sick pay insurance, you'll be asked for the following details:

  • Date of diagnosis
  • Your symptoms, past and present
  • Treatment and medication, past and present
  • Any other conditions related to your thyroid condition
  • How the condition affects your daily life, if at all
  • Any time you had to take off work due to your condition
  • Any planned surgery
  • Your most recent results showing your Thyroid-Stimulating Hormone (TSH) levels (if you don't have these, the insurer will request this information from your doctor)

Will a life insurance company write to my doctor about my thyroid condition?

Providing as much information as you can to the insurer will help avoid requests to your GP surgery and in turn the delays that this can cause to your application. In some cases, the insurer may still have to write to your GP to access more detailed information about your health than you are able to provide. If you're at all unsure about any of your health information, you should simply request that the insurer writes to your GP for clarification. Remember that any claim against the policy will be checked and the information on your application must match your health records to ensure the claim is paid.

How do thyroid conditions impact life insurance premiums?

Overactive thyroid & Underactive thyroid

Your condition is unlikely to change the cost of your life insurance, so long as your symptoms are controlled and your TSH levels are within the normal range. Do keep in mind that TSH levels can vary due to pregnancy, menstrual cycles and if you are receiving treatment for other conditions.

Age-Related Range for Thyroid-Stimulating Hormones (TSH)

Age range Normal Low High
18-30 years 0.5 - 4.1 mU/L < 0.5 mU/L > 4.1 mU/L
31-50 years 0.5 - 4.1 mU/L < 0.5 mU/L > 4.1 mU/L
51-70 years 0.5 - 4.5 mU/L < 0.5 mU/L > 4.5 mU/L
71-90 years 0.4 - 5.2 mU/L < 0.4 mU/L > 5.2 mU/L


If you have ongoing symptoms and/or your TSH levels are outside of the normal range (displayed in the table above) for a period of 3 months or more, you may need specialist advice in order to ensure you get the best and cheapest life insurance for your needs. We explain more about how to do this below.

Can I get critical illness insurance if I have a thyroid condition?

Yes, if your symptoms are controlled and your TSH levels are within the normal range then it should be straightforward to arrange Critical Illness Insurance even if your treatment is ongoing. If your symptoms are continuing and/or your TSH levels are not within the normal range over at least a 3 month period, you may need specialist advice to arrange your critical illness insurance. You can jump ahead to read more about how to do this here.

Can I get income protection insurance if I have a thyroid condition?

Again, your symptoms and results confirming your TSH levels will determine if your application for income protection will be accepted. This type of application will focus more heavily on the impact that your condition has had on your ability to work. If you have had a lot of time off work due to your thyroid condition over the last 2 years then this might mean that you'll have to wait until your symptoms have been controlled for a longer period of time.

However, it is always worth talking it through with a specialist insurance adviser who may help to find an insurer that is willing to offer insurance sooner. If the insurer does want to wait before offering the insurance (referred to as a postponement), then you'll be told how long you'll need to wait before an application may be considered. Read on to find out you can save time and effort by doing some groundwork before you apply.

Which is the best life insurance company if I have a thyroid condition?

It can be difficult to pin down the most favourable insurers if you have a thyroid condition, especially when insurers have been known to change their underwriting guidelines from time to time. What we can confirm is that applications can take both time and effort to pursue and so it is best to apply to a company that is likely to accept your application and provide the best and cheapest cover. The way to be sure of this is to enlist the help of a specialist insurance adviser who will research the best cover based on your specific circumstances. This way, you'll know what to expect before you complete any application forms. It is a valuable resource and is often free to access.

Like any service, there are good brokers and not-so-good ones. With that in mind, we had a look around ourselves and have personally vetted a specialist independent life insurance broker. You'll be put in touch with an adviser who will take your details, do all the necessary research and point you in the direction of a solution that works for you. You'll save time and can be certain that you're getting the best price available.

To arrange a call from a specialist insurance adviser, simply complete this form and one will be in touch. You'll even get £50 cashback as a Money to the Masses reader.



If a link has an * beside it this means that it is an affiliated link. If you go via the link, Money to the Masses may receive a small fee which helps keep Money to the Masses free to use. This link can be used if you do not wish to help Money to the Masses and do not wish to qualify for the cashback referred to in the article