Is hypothyroidism genetic?

Written on March 7, 2023 by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

• About hypothyroidism
• The function of thyroid hormones
• Hypothyroidism symptoms
• Genetic parts of hypothyroidism
• Causes of hypothyroidism
• Testing and next steps for hypothyroidism management
• Related content

About hypothyroidism

Hypothyroidism is an underactive thyroid condition where there are not enough thyroid hormones for your body to function and use energy [1,2]. The thyroid is a “small, butterfly-shaped gland” on the front lower side of your neck. The primary role of the thyroid gland is to produce thyroid hormones to be released into the blood [2]. About 5 out of 100 people in the United States, 12 years and older, have hypothyroidism [1].

Anyone can develop hypothyroidism; however, you are at an increased risk if you [1,3]:

• Are a female
• Have a family history of thyroid disorders
• Have an autoimmune disease (for example, type 1 diabetes or celiac disease)
• Received treatment for hyperthyroidism, radiation therapy near your neck or upper chest, or thyroid surgery

The function of thyroid hormones

The thyroid gland produces two major hormones: thyroxine (T-4) and triiodothyronine (T-3) [3]. Thyroid hormones are vital to the body working appropriately [3,4]. Thyroid hormones help to regulate how your body uses energy and impact almost every organ [1]. It functions to keep the body warm and keeps organs such as the brain, heart, and muscles working as they should [2]. Without adequate thyroid hormones, bodily functions essentially decrease [1].

Hypothyroidism symptoms

You may not notice symptoms or know you have the disease because hypothyroidism symptoms can slowly manifest and may take years [1]. Symptoms can differ from one person to another, and you may think some symptoms are just part of aging [3]. Some of the common signs of an underactive thyroid include [1-3]:

• Weight gain
• Fatigue
• Joint and muscle pain
• Dry skin
• Dry, thinning hair
• Slow heart rate
• Irregular, heavy menstrual cycles
• Fertility issues
• Difficulty tolerating cold
• Memory problems
• Depression
• Constipation

Genetic parts of hypothyroidism

Hypothyroidism has genetic elements to the condition. It is estimated that up to 65% of circulating T-3 and T-4 hormones are genetically determined [4]. Although the exact genes responsible for thyroid hormones have yet to be identified, a few genes are associated with thyroid function and clinical presentation [4]. Genes with variants or mutations and the interactions of multiple genes can be involved in the metabolism of thyroid hormones and affect the development of thyroid diseases [5]. A family history of thyroid disease is a risk factor for hypothyroidism [3].

Several other thyroid conditions also have a genetic component. Congenital hypothyroidism is a rare thyroid disorder in newborn babies with insufficient thyroid hormones [3,6]. Multiple gene defects with inherited mutations have been implicated in congenital hypothyroidism [6]. About 20%-30% of people with hypothyroidism are affected by an autoimmune condition called Hashimoto’s disease [7,8]. The cause of Hashimoto’s disease is thought to be partly genetics and typically results in the body attacking the thyroid gland [8].

Causes of hypothyroidism

Hypothyroidism may be caused by genetic and environmental, including [1-3]:

• Hashimoto’s disease is the most common autoimmune thyroid disorder where your body’s immune system attacks the thyroid.
• Congenital hypothyroidism is a rare condition where babies may be born without a thyroid, only a part of a thyroid, with the thyroid in the wrong part of the body, or with dysfunctional thyroid cells.
• Thyroiditis is the inflammation of the thyroid gland that can lead to the release of all thyroid hormones at once, causing brief hyperthyroidism. Then the thyroid becomes underactive, initiating hypothyroidism.
• The surgical removal of all or a section of the thyroid gland for hyperthyroidism therapy can cause hypothyroidism. What is left after surgery may not be enough to produce adequate thyroid hormones for the body.
• Radiation treatment of the thyroid as part of hyperthyroidism, lymphoma, or other cancers can lead to loss of thyroid functioning.
• Medications, such as amiodarone or lithium, can prevent the thyroid gland from functioning normally and trigger hypothyroidism in some patients.
• Not enough or too much iodine can cause hypothyroidism. Iodine comes from your food, and keeping a good balance of levels is essential for adequate thyroid hormone levels.
• A damaged pituitary gland resulting from a tumor, radiation, or surgery can lead to the thyroid not making enough hormones. The pituitary gland is responsible for letting the thyroid gland know how many hormones to produce.
• Rare disorders affecting the thyroid, such as hemochromatosis or sarcoidosis, can deposit substances in the thyroid gland and alter proper functioning.

Testing and next steps for hypothyroidism management

Various tests can be ordered to help confirm a diagnosis of hypothyroidism, based on your symptoms, medical and family history, and a physical exam [2]. Your provider can help recommend testing and the next steps for you.

Another option is at-home lab testing. At-home thyroid blood tests, such as the Everlywell Thyroid Test, are a convenient starting point for determining whether you may have a thyroid condition and will indicate to you what you should do next.

At Everlywell, you can also schedule an online thyroid telehealth visit if you think you have symptoms related to your thyroid. You can discuss symptoms like fatigue, restlessness, mood changes, cold sensitivity, or weight changes with a healthcare provider for treatment recommendations, which may include prescription of thyroid medication online.

Related content

Are thyroid problems genetic?

Causes of thyroid problems

How to test for hypothyroidism

References

1. Hypothyroidism (underactive thyroid). National Institute of Diabetes and Digestive and Kidney Diseases. URL. Published March 2021. Accessed March 7, 2023.
2. Hypothyroidism. American Thyroid Association. URL. Accessed March 7, 2023.
3. Hypothyroidism (underactive thyroid). Mayo Clinic. URL. Published December 10, 2022. Accessed March 7, 2023.
4. Panicker V. Genetics of thyroid function and disease. Clin Biochem Rev. 2011;32(4):165-175.
5. Cortés JMR, Zerón HM. Genetics of thyroid disorders. Folia Med (Plovdiv). 2019;61(2):172-179. doi: 10.2478/folmed-2018-0078. URL.
6. Schoenmakers N. The genetic basis of congenital hypothyroidism. Society for Endocrinology. URL. Accessed March 7, 2023.
7. Hashimoto’s disease. Mayo Clinic. URL. Published January 15, 2022. Accessed March 7, 2023.
8. Ragusa F, Fallahi P, Elia G, et al. Hashimotos’ thyroiditis: epidemiology, pathogenesis, clinic and therapy. Best Pract Res Clin Endocrinol Metab. 2019;33(6):101367. doi: 10.1016/j.beem.2019.101367. URL.