Health Topic

Thyroid Diseases

The thyroid is a gland in the neck. The thyroid gland creates hormones that affect metabolism. Learn about thyroid diseases, such as hypothyroidism.

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Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Thyroid Diseases

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods.

Thyroid diseases cause your thyroid to make either too much or too little of the hormones. Some of the different thyroid diseases include:

  • Goiter, an enlargement of the thyroid gland
  • Hyperthyroidism, which happens when your thyroid gland makes more thyroid hormones than your body needs
  • Hypothyroidism, which happens when your thyroid gland does not make enough thyroid hormones
  • Thyroid cancer
  • Thyroid nodules, lumps in the thyroid gland
  • Thyroiditis, swelling of the thyroid

To diagnose thyroid diseases, your health care provider may use a medical history, physical exam, and thyroid tests. In some cases, your provider may also do a biopsy.

Treatment depends on the problem, how severe it is, and what your symptoms are. Possible treatments may include medicines, radioiodine therapy, or thyroid surgery.

Dept. of Health and Human Services Office on Women's Health

It sits within Endocrine System.

The lead U.S. institute for this subject is the National Institute of Diabetes and Digestive and Kidney Diseases.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Thyroid Diseases

2,418 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Diagnosis and Tests

Treatments and Therapies

Related Issues

Genetics

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Thyroid Diseases. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Thyroid Diseases, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.