Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentOther Types of HypothyroidismFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Other Types of Hypothyroidism
Frequently Asked Questions
Secondary (central)hypothyroidismoccurs when the pituitary gland does not produce or release enoughthyroid-stimulating hormone(TSH). TSH is required for normal stimulation and functioning of the thyroid.
The thyroid—a small, butterfly-shaped gland at the front of your neck—produces the thyroid hormonesthyroxine(T4) andtriiodothyronine(T3).These hormones are released into the bloodstream and carried to the body’s organs and tissues. Thyroid hormones regulate your metabolism and affect nearly every process in the body, including body temperature, heart rate, appetite, blood sugar, cholesterol levels, and the central nervous system.
This article explores secondary hypothyroidism symptoms, causes, treatments, and more.
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Secondary Hypothyroidism Symptoms
Secondary hypothyroidism can affect virtually all body functions and cause various symptoms ranging from mild to severe.
Symptoms of secondary hypothyroidism include:
Secondary hypothyroidism occurs when an otherwise normal, healthythyroid glanddoes not get enough thyroid-stimulating hormone (TSH) from thepituitary glandto stimulate hormone production. Anatomical differences, or disorders of the pituitary gland and/orhypothalamus(a part of the brain that regulators numerous body functions), are associated with secondary hypothyroidism.
Causes of secondary hypothyroidism include:
Risk Factors for Secondary HypothyroidismA pituitary tumor is the most common cause of secondary hypothyroidism. Other risk factors include:Personal or family history of thyroid diseaseHaving anautoimmune conditionHistory of radiation therapyPituitary gland and/or hypothalamus dysfunctionSecondary hypothyroidism is also more prevalent in females and people over age 60.
Risk Factors for Secondary Hypothyroidism
A pituitary tumor is the most common cause of secondary hypothyroidism. Other risk factors include:Personal or family history of thyroid diseaseHaving anautoimmune conditionHistory of radiation therapyPituitary gland and/or hypothalamus dysfunctionSecondary hypothyroidism is also more prevalent in females and people over age 60.
A pituitary tumor is the most common cause of secondary hypothyroidism. Other risk factors include:
Secondary hypothyroidism is also more prevalent in females and people over age 60.
If you havesymptoms of hypothyroidism, talk to your healthcare provider. They will perform a physical examination, take your vital signs, and manually check the size of your thyroid gland.
If your thyroid is small or you have a slow heart rate, low temperature, or low blood pressure, your healthcare provider may order blood tests to determine whether you haveprimaryor secondary hypothyroidism.
Thyroid blood testsinclude:
If you are diagnosed with secondary hypothyroidism, your healthcare provider may order imaging tests, such as magnetic resonance imaging (MRI), to check for tumors on the pituitary gland. Genetic testing may be ordered to determine if gene mutations are the cause of secondary hypothyroidism.
Once treatment begins, symptoms of secondary hypothyroidism may resolve within several weeks.Your healthcare provider will check your TSH levels six to 10 weeks after starting treatment to see how well the medication works and make dosage adjustments as needed. Once thyroid hormone levels stabilize, your healthcare provider will most likely check your levels once a year.
There is no cure for hypothyroidism, so lifelong treatment may be necessary. It’s important to continue taking your prescribed medication, even when your symptoms subside.
If a pituitary or hypothalamic disorder causes secondary hypothyroidism, treatments for the underlying cause may be needed before hormone replacement therapy begins.A pituitary tumor, for example, should be removed during a surgical procedure before hormone replacement therapy begins.
There are three other types of hypothyroidism:
Primary hypothyroidism: Occurs when the thyroid gland fails to produce sufficient thyroid hormones. Approximately 99% of all people with hypothyroidism have this type.
Tertiary hypothyroidism: Occurs when the pituitary gland secretes deficient levels of TSH as a result of the hypothalamus producing insufficient levels ofthyrotropin-releasing hormone (TRH).
Subclinical hypothyroidism: Also known as mild thyroid failure, this type is associated with slightly elevated TSH levels and normal levels of other thyroid hormones (e.g., T3, T4).
Complications of Secondary HypothyroidismIf left untreated, hypothyroidism may lead tomyxedema coma, a rare complication associated with progressive cognitive deterioration, skin swelling,hypothermia, an enlarged tongue, coarse hair, and organ abnormalities.Myxedema can be life-threatening and requires immediate medical attention and treatment.
Complications of Secondary Hypothyroidism
If left untreated, hypothyroidism may lead tomyxedema coma, a rare complication associated with progressive cognitive deterioration, skin swelling,hypothermia, an enlarged tongue, coarse hair, and organ abnormalities.Myxedema can be life-threatening and requires immediate medical attention and treatment.
Summary
A pituitary tumor is the most common cause of secondary hypothyroidism. Other causes include a personal or family history of thyroid disease, previous radiation therapy to the head or neck, and hypothalamus dysfunction.
Thyroid hormone replacement therapy is the standard line of treatment for secondary hypothyroidism. Levothyroxine is an oral medication commonly prescribed to help restore thyroid hormone levels to the normal range and reduce or eliminate symptoms.
A Word From Verywell
Secondary hypothyroidism can make you feel fatigued and generally unwell. The good news is that the condition is highly treatable. Thyroid hormone replacement therapy can help restore and stabilize thyroid hormone levels to help you feel your best.
There is no cure for secondary hypothyroidism, but it is a highly treatable condition. Levothyroxine is the most commonly prescribed medication for hypothyroidism.Taken orally once a day, levothyroxine helps restore and stabilize thyroid hormone levels to reduce or eliminate symptoms of hypothyroidism. Lifelong treatment may be required for secondary hypothyroidism.
13 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Merck Manual: Consumer Version.Hypothyroidism.Government of Western Australia.The thyroid gland.Merck Manual: Professional Version.Hypothyroidism.Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515Endocrinology Advisor.Central hypothyroidism.MedlinePlus.Hypothyroidism.JoVE Science Education Database.Physical examinations II. thyroid exam.Sheehan MT.Biochemical testing of the thyroid: tsh is the best and, oftentimes, only test needed - a review for primary care.Clin Med Res. 2016;14(2):83-92. doi:10.3121/cmr.2016.1309American Thyroid Association.Hypothyroidism (underactive thyroid).United Kingdom National Health Service.Levothyroxine.Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515Chiovato L, Magri F, Carlé A.Hypothyroidism in context: where we’ve been and where we’re going.Adv Ther. 2019;36(Suppl 2):47-58. doi:10.1007/s12325-019-01080-8The Pharmaceutical Journal.Hypothyroidism: causes, diagnosis and treatment.
13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Merck Manual: Consumer Version.Hypothyroidism.Government of Western Australia.The thyroid gland.Merck Manual: Professional Version.Hypothyroidism.Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515Endocrinology Advisor.Central hypothyroidism.MedlinePlus.Hypothyroidism.JoVE Science Education Database.Physical examinations II. thyroid exam.Sheehan MT.Biochemical testing of the thyroid: tsh is the best and, oftentimes, only test needed - a review for primary care.Clin Med Res. 2016;14(2):83-92. doi:10.3121/cmr.2016.1309American Thyroid Association.Hypothyroidism (underactive thyroid).United Kingdom National Health Service.Levothyroxine.Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515Chiovato L, Magri F, Carlé A.Hypothyroidism in context: where we’ve been and where we’re going.Adv Ther. 2019;36(Suppl 2):47-58. doi:10.1007/s12325-019-01080-8The Pharmaceutical Journal.Hypothyroidism: causes, diagnosis and treatment.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Merck Manual: Consumer Version.Hypothyroidism.Government of Western Australia.The thyroid gland.Merck Manual: Professional Version.Hypothyroidism.Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515Endocrinology Advisor.Central hypothyroidism.MedlinePlus.Hypothyroidism.JoVE Science Education Database.Physical examinations II. thyroid exam.Sheehan MT.Biochemical testing of the thyroid: tsh is the best and, oftentimes, only test needed - a review for primary care.Clin Med Res. 2016;14(2):83-92. doi:10.3121/cmr.2016.1309American Thyroid Association.Hypothyroidism (underactive thyroid).United Kingdom National Health Service.Levothyroxine.Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515Chiovato L, Magri F, Carlé A.Hypothyroidism in context: where we’ve been and where we’re going.Adv Ther. 2019;36(Suppl 2):47-58. doi:10.1007/s12325-019-01080-8The Pharmaceutical Journal.Hypothyroidism: causes, diagnosis and treatment.
Merck Manual: Consumer Version.Hypothyroidism.
Government of Western Australia.The thyroid gland.
Merck Manual: Professional Version.Hypothyroidism.
Persani L, Cangiano B, Bonomi M.The diagnosis and management of central hypothyroidism in 2018.Endocr Connect. 2019;8(2):R44-R54. doi:10.1530/EC-18-0515
Endocrinology Advisor.Central hypothyroidism.
MedlinePlus.Hypothyroidism.
JoVE Science Education Database.Physical examinations II. thyroid exam.
Sheehan MT.Biochemical testing of the thyroid: tsh is the best and, oftentimes, only test needed - a review for primary care.Clin Med Res. 2016;14(2):83-92. doi:10.3121/cmr.2016.1309
American Thyroid Association.Hypothyroidism (underactive thyroid).
United Kingdom National Health Service.Levothyroxine.
Chiovato L, Magri F, Carlé A.Hypothyroidism in context: where we’ve been and where we’re going.Adv Ther. 2019;36(Suppl 2):47-58. doi:10.1007/s12325-019-01080-8
The Pharmaceutical Journal.Hypothyroidism: causes, diagnosis and treatment.
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