The thyroid is a butterfly-shaped gland that is on the front of the neck. Your thyroid is located under the Adam’s apple, along the front of the windpipe. You cannot feel thyroid when it is at its normal size.
The thyroid is brownish red in color, rich in blood vessels. The nerves important for the quality of the voice also pass through the thyroid.
The thyroid secretes several hormones, called thyroid hormones. The main hormone is thyroxine, also called T4. During childhood and infancy, adequate thyroid hormone is crucial for brain development.
Thyroid disorders
- Goiter: a general term for swelling of the thyroid. Goiter may be harmless or represent iodine deficiency or a condition associated with an inflamed thyroid called Hashimoto’s thyroiditis.
- Thyroiditis: inflammation of the thyroid, usually due to a viral infection or autoimmune disease. Thyroiditis may be painful or have no symptoms.
- Hyperthyroidism: excessive production of thyroid hormones. Hyperthyroidism is most often caused by Graves’ disease or by an overactive thyroid nodule.
- Hypothyroidism: low production of thyroid hormone. The most common cause of hypothyroidism is thyroid damage caused by an autoimmune disease.
- Graves’ disease: an autoimmune disease in which the thyroid is overstimulated, causing hyperthyroidism.
- Thyroid Cancer: A rare form of cancer, thyroid cancer is usually curable. Surgery, radiation therapy, and hormonal treatments can be used to treat thyroid cancer.
- Thyroid nodule: a small, abnormal lump or lump in the thyroid gland. Thyroid nodules are extremely common. Few of them are cancerous. They can secrete excess hormones, causing hyperthyroidism or not causing any problems.
- Thyroid storm: a rare form of hyperthyroidism in which extremely high levels of thyroid hormones cause serious illness.
Thyroid tests
- Anti-TPO Antibodies: In autoimmune thyroid disease, proteins attack the enzyme thyroid peroxidase by mistake, which is used by the thyroid to make thyroid hormones.
- Thyroid ultrasound: On the skin of the neck, a probe is placed and the reflected sound waves can detect abnormal areas of thyroid.
- Thyroid scan: a small amount of radioactive iodine is secreted by mouth to get images of the thyroid gland. Radioactive iodine is concentrated in the thyroid gland.
- Thyroid biopsy: A small amount of thyroid tissue is taken, usually to check for thyroid cancer. The thyroid biopsy is usually done with a needle.
- Thyroid Stimulating Hormone (TSH): Secreted by the brain, TSH regulates the release of thyroid hormones. A blood test with an elevated TSH indicates low levels of thyroid hormones (hypothyroidism) and a low TSH suggests hyperthyroidism.
- T3 and T4 (thyroxine): the main forms of thyroid hormone, checked by a blood test.
- Thyroglobulins: a substance secreted by the thyroid that can be used as a marker for thyroid cancer. During follow-up in patients with thyroid cancer, it is often measured. High levels indicate cancer recurrence.
- Other imaging tests: If thyroid cancer has spread (metastasized), tests such as CT scans, MRIs, or PET scans can help identify the extent of the spread.
Thyroid treatments
- Thyroid surgery (thyroidectomy): A surgeon removes all or part of the thyroid during an operation. Thyroidectomy is performed for goiter, hyperthyroidism, or thyroid cancer.
- Antithyroid Drugs: Drugs can slow down the overproduction of thyroid hormones in hyperthyroidism. Two common antithyroid drugs are methimazole and propylthiouracil.
- Radioactive iodine: Radioactive iodine that can be used in low doses to test the thyroid gland or destroy an overactive gland. To destroy cancerous tissue, large doses can be used.
- External radiation: A beam of radiation is directed towards the thyroid, during several appointments. Thyroid cancer cells are killed by the high energy rays.
- Thyroid hormone pills: A daily treatment that replaces the amount of thyroid hormone that you can no longer make. Thyroid hormone pills treat hypothyroidism and are also used to help prevent thyroid cancer after treatment.
- Recombinant human TSH: Injection of this thyroid stimulating agent may show thyroid cancer more clearly on imaging tests.
