Thyroid Cancer and Hypertension

thyroid cancer, hypertension, high blood pressure, cardiomyopathy
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Hypertension (high blood pressure) is one of the common effects of thyroid cancer. If you have or have had thyroid cancer, it is important to be aware of the risk of developing hypertension. The long-term effects of high blood pressure produce a number of health problems over time, including increased strokes, heart attacks, kidney disease, and dementia.

If you have thyroid cancer or if you have been treated for thyroid cancer, you need to be on the lookout for hypertension throughout and after your thyroid cancer treatment, as there is a lasting risk of developing hypertension, even after thyroid cancer is fully treated.

Thyroid Cancer and Hypertension

Thyroid cancer is not a common type of cancer. If you are being evaluated for possible thyroid cancer, you should know that there are several different types, including papillary thyroid cancer (the most common type), follicular thyroid cancer, medullary thyroid cancer, and anaplastic thyroid cancer. These cancers differ based on their symptoms, how rapidly they grow and spread, and their microscopic appearance.

How Thyroid Cancer Causes Hypertension

All thyroid cancers can increase or decrease the production of your thyroid hormones and may induce symptoms of hyperthyroidism (overactivity of thyroid hormones) or hypothyroidism (under activity of thyroid hormones). Generally, thyroid cancer is more often associated with hyperthyroidism than with hypothyroidism.

Understanding Thyroid Tests

Hyperthyroidism results in increased metabolism and usually causes increased blood pressure. Hypothyroidism is usually associated with normal blood pressure but it can cause low blood pressure or high blood pressure.

Interestingly, thyroid cancer is likely to cause high blood pressure whether it produces hyperthyroidism or hypothyroidism.

Symptoms of Thyroid Cancer

Often, a nodule, a growth, or a goiter can be the first sign of thyroid cancer. Other symptoms include weight changes, fatigue, or agitation. Sometimes, unexplained hypertension, especially if it begins at an unusually young age or is not easily managed with medication, can prompt an evaluation of your thyroid function and may lead to a diagnosis of thyroid cancer.

Thyroid Cancer Treatment and Hypertension

There are a number of treatment strategies used for thyroid cancer, including chemotherapy, radiation, surgery, and thyroid replacement medications after treatment. These approaches, while necessary, can induce hypertension.

Chemotherapy

Several of the chemotherapeutic medications used for thyroid cancer have been shown to cause high blood pressure. Pazopanib, cabozantinib, and vandetanib are all classified as tyrosine kinase inhibitors, a common type of chemotherapy, and they have all been linked to hypertension when used for the treatment of thyroid cancer. The exact mechanism of this effect is not known.

Thyroid Cancer: Options for Treatment

Surgery

Surgical treatment for thyroid cancer has also been associated with hypertension. There are several known reasons for this reaction. Removal of the thyroid gland stimulates an increase in thyroid stimulating hormone (TSH), which can cause overproduction of thyroid hormones from the remaining thyroid gland. In some instances, a condition called thyroid storm can occur, which is a severe rise in thyroid hormones that can cause a sudden increase in metabolism and blood pressure.

Thyroid Replacement Medications

After recovery from thyroid cancer, you may need to take thyroid hormone replacement medications, especially if you have had surgery or radiation. Generally, thyroid hormone replacement is aimed at achieving optimal thyroid function. However, excess thyroid hormone replacement can induce hypertension, while inadequate levels of thyroid hormone replacement can cause your body to overcompensate, possibly producing hormones (such as adrenal hormones) that trigger hypertension.

Over time, your thyroid replacement medication can be adjusted so that you can get just the right amount of thyroid hormone.

After recovering from thyroid cancer, there is an increased risk of hypertension among survivors. The cause of this association is not clear, and it can happen even if you have normal thyroid hormone levels.

Recognizing and Treating Hypertension

Hypertension does not usually cause any symptoms unless there is a hypertensive crisis, which is rare. You cannot expect yourself to recognize hypertension — it is identified during a physical examination, using a blood pressure cuff.

You can also purchase a blood pressure cuff so that you can check your own blood pressure at home. Sometimes, local pharmacies or community centers have blood pressure cuffs available as well.

If you are diagnosed with hypertension, there are effective prescription medications that can control your blood pressure. Because thyroid disease, thyroid treatment, and thyroid replacement medications can all interfere with your blood pressure, you may need the dose of your blood pressure medication adjusted as your thyroid function changes during your cancer treatment and after your recovery.

A Word From Verywell

Hypertension is very common, but if you have or have had thyroid cancer, you have an even greater chance of developing the condition.

If you are recovering from thyroid cancer, it is a good idea to familiarize yourself with the most updated recommendations for your target blood pressure so that you can let your doctor know right away if your blood pressure changes.

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