Patient Education

Glossary of Endocrinology Terms

Endocrinology
A branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions called hormones, the integration of developmental events such as proliferation, growth, differentiation and the coordination of metabolism, respiration, excretion, movement, reproduction, and sensory perception depend on chemical cues, substances synthesized and secreted by specialized cells.
Endocrinologist
Is a specially trained doctor. Endocrinologists diagnose diseases that affect your glands. Endocrinologists are trained to diagnose and treat hormone imbalances and problems by helping to restore the normal balance of hormones in your system.
Thyroid Gland
An important organ of the endocrine system. It is located in the front of the neck just below the voice box. The gland produces the hormones thyroxine (T4) and triiodothyronine (T3), which control the way every cell in the body uses energy. This process is called metabolism.
Thyroid Goiter
A swelling of the neck or larynx resulting from enlargement of the thyroid gland (thyromegaly). Worldwide, the most common cause for goiter is iodine deficiency, usually seen in countries that do not use iodized salt. Selenium deficiency is also considered a contributing factor. In countries that use iodized salt, Hashimoto's thyroiditis is the common cause. Most common cause for thyroid enlargement ( goiter) is due to presence of thyroid nodules in side of thyroid gland.
Thyroid Nodule
An abnormal growth of thyroid cells that forms a lump within the thyroid gland. Majority of thyroid nodules are benign (noncancerous), a small proportion of thyroid nodules do contain thyroid cancer. In order to diagnose and treat thyroid cancer at the earliest stage, thyroid nodules needs to be evaluated.
Thyroid Cancer
A malignant neoplasm originating from follicular or parafollicular thyroid cells. Most commonly an ultrasound is performed to confirm the presence of a nodule, and assess the status of the whole gland. There are some features on ultrasound which puts thyroid nodule in higher risk for being cancerous. 1. Microcalcifications and irregular borders, 2. Increase vascular flow on Doppler study. Classification of Thyroid Cancer: Thyroid cancers can be classified according to their histological characteristics.The following variants can be distinguished (distribution over various subtypes may show regional variation): Papillary thyroid cancer (75% to 85% of cases ). Follicular thyroid cancer (10% to 20% of cases). Medullary thyroid cancer (5% to 8% of cases)- cancer of the parafollicular cells, often part of MEN type 2. Anaplastic thyroid cancer (less than 5%). It is not responsive to treatment and can cause pressure symptoms. Poorly differentiated thyroid cancer Others: Thyroid lymphoma, sarcoma of thyroid. The follicular and papillary types together can be classified as "differentiated thyroid cancer".These types have a more favorable prognosis than the medullary and undifferentiated types.
Hypothyroidism
A state in which the thyroid gland does not make enough thyroid hormone. Symptoms of hypothyroidism are fatigue or decrease of energy, feeling cold, constipation, weight gain, hair loss, edema or swollen legs, visual changes, heavy and irregular periods, infertility.
Hyperthyroidism
A condition in which the thyroid gland makes too much thyroid hormone. The condition is often referred to as an "overactive thyroid." Most common symptoms of hyperthyroidism are rapid heart rate, diarrhea, chest pain, feeling hot, visual changes, weight loss, hyperhydrosis, irregular menstrual periods, infertility, fatigue. Most common causes for hyperthyroidisms are Graves' disease, toxic multinodular goiter or toxic adenoma.
Iodine Deficiency
often cited as the most common cause of hypothyroidism worldwide but it can be caused by many other factors. It can result from a lack of a thyroid gland or from iodine-131 treatment, and can also be associated with increased stress.
Cushing's Syndrome
Describes the signs and symptoms associated with prolonged exposure to inappropriately high levels of the hormone cortisol.
Adrenal Glands
Endocrine glands that sit at the top of the kidneys. Tumors of the adrenal glands are rare. When present, they can cause a multitude of disorders by excessively secreting certain adrenal gland produced hormones. However most of them are not producing any hormones. Non hormone producing (non-functional) adrenal tumors are called incidentaloma. Only a small percent of adrenal tumors are cancerous.

Celebrities with Endocrine Problems:

  • Oprah Winfrey announced her thyroid problems in 2007. Before she was diagnosed with hypothyroidism, she struggled with weight gain and felt exhausted all the time.
  • Famous film critic Roger Ebert was diagnosed with papillary thyroid cancer in 2002.
  • TV’s toughest trainer and fitness guru Jillian Michaels has worked hard to manage her hypothyroidism.
  • Musician and singer-songwriter Rod Stewart was diagnosed with thyroid cancer in 2000. He had to re-learn how to sing after his thyroid cancer surgery.
  • Former President George H. W. Bush was diagnosed with Graves' disease in 1991 and was treated with radioactive iodine. His wife, former First Lady Barbara Bush, was also diagnosed with Graves' disease around the same time.
  • Actress and screenwriter Nia Vardalos, best known for her role in My Big Fat Greek Wedding, has Hashimoto’s thyroiditis.
  • Joan Rivers is one of the near-44 million women in the US with osteoporosis.