Thyroid Cancer's Connection to Cardiovascular Disease

The cancer, and its treatments, can pose a risk to your heart health

Cardiovascular (CVD) disease—encompassing heart disease, stroke, aortic aneurysms, and other concerns—is one of the long-term consequences of thyroid cancer. There are several contributing factors for this association, both related to the disease itself and its treatments. Unfortunately, even when thyroid cancer is treated adequately, CV disease can develop.

Remember to check your blood pressure regularly
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What Poses Risk to Your Cardiovascular Health

There are several reasons for the association between thyroid cancer and CV disease. Thyroid cancer can produce several physical effects, some of which directly contribute to the development of cardiovascular issues.

Several of the therapeutic methods used to treat thyroid cancer also contribute to the development of cardiovascular disease.

Levothyroxine Suppression

After surgical removal of the thyroid gland and, in some cases, after treatment with radioactive iodine, you may be given a prescription for a high dose of levothyroxine. This medication is a thyroid hormone replacement, and high doses (known as supraphysiologic doses) are used to suppress the thyroid-stimulating hormone (TSH) level. Keeping very low or undetectable TSH levels can prevent the recurrence of thyroid cancer.

However, the use of supraphysiologic doses of levothyroxine is also strongly associated with an increased risk of CV disease and atrial fibrillation.


Removing thyroid cancer by completely resecting the thyroid gland is associated with a lower risk of cancer recurrence, but a slightly higher risk of cardiovascular disease, as recently shown by a retrospective analysis.

Radioactive Iodine

Used for treatment of thyroid cancer, radioactive iodine binds to and destroys cancerous thyroid tissue, as well as normal tissue in the thyroid gland. Treatment with radioactive iodine has been linked with a high occurrence of CV disease after thyroid cancer, though the reasons why are not clear.

The additive effects of thyroid cancer and its treatment mean that CV disease is a real concern if you have or have had thyroid cancer.

Managing Your Cardiovascular Disease Risk When You Have Thyroid Cancer

If you have or have had thyroid cancer, it is important to understand that adequate cancer treatment does not mean that you no longer have to deal with some of the complications of cancer.

While it can be upsetting to know that your cancer effects have not truly disappeared after treatment of the tumor, CV disease risk factors can be effectively managed.

Be sure to maintain regular medical visits with your healthcare provider, as yearly physicals routinely include measurements of your blood pressure and assessments of your heart rhythm (which can help your healthcare provider detect atrial fibrillation). That said, don't hesitate to make an earlier appointment if you are experiencing any symptoms you are concerned about.

If you have signs of heart disease or hypertension, your healthcare provider may prescribe medication to regulate your heart rhythm, optimize your blood pressure, or reduce your risk of developing a blood clot.

Thyroid Cancer Healthcare Provider Discussion Guide

Get our printable guide for your next healthcare provider's appointment to help you ask the right questions.

Doctor Discussion Guide Woman

A Word From Verywell

If you have or have had thyroid cancer, you should know that there are several types of thyroid cancer, and the prognosis varies depending on which type you have. As you are dealing with treatment for your cancer, you also need to be attentive to how your cancer and your thyroid function can affect your health. With attention, effects of thyroid cancer and thyroid disease can be managed to reduce the impact of your condition on your overall health.

1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Park J, Blackburn BE, Ganz PA, et al. Risk factors for cardiovascular disease among thyroid cancer survivors: findings from the Utah Cancer Survivors Study. J Clin Endocrinol Metab. 2018;103(7):2468-2477. doi:10.1210/jc.2017-02629

Additional Reading

By Mary Shomon
Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution."