The thyroid gland is a small, butterfly-shaped organ in the throat that is very important to health and wellbeing. The thyroid is part of the endocrine system, which is essentially a collection of glands. These glands produce hormones that regulate mood and other various functions in the body — and the thyroid gland is no different.

"Thyroid hormones impact a host of vital body functions, including heart rate, skin maintenance, growth, temperature regulation, fertility and digestion,” said the late Dr. Jerome M. Hershman, former emeritus professor of medicine at the David Geffen School of Medicine at the University of California, Los Angeles.

But how big is the thyroid gland? What is its exact function? And what thyroid conditions should you know about? Keep reading to discover everything there is to know about this organ.

Thyroid gland: Size

The thyroid gland is 2 inches (5 centimeters) wide and weighs between 20 and 60 grams (0.7 to 2.1 ounces), according to the U.S. National Library of Medicine.

The gland stretches across the front of the neck, below the voice box. Like a butterfly, it has two wings called lobes that stretch around the windpipe. The wings are connected by a small piece called the isthmus.

Thyroid gland: Function

The thyroid gland controls just about every cell in the human body. It secretes hormones calcitonin, T4 (thyroxine or tetraiodothyronine) and T3 (triiodothyronine) into the bloodstream. The hormones control the rate at which cells and organs turn nutrients into energy and the amount of oxygen cells use.

"In this way, the thyroid gland is the body's master metabolic control center," said Cindy Samet, a chemistry professor at Dickinson College in Carlisle, Pennsylvania. "Brain, heart and kidney function, as well as body temperature, growth and muscle strength — and much more — are at the mercy of thyroid function."

Dr. Melanie GoldfarbSocial Links Navigation

Endocrinologist

After graduating from Brown University and the University of Illinois College of Medicine, Goldfarb completed her general surgery residency at Harvard Medical School and endocrine surgery fellowship at the University of Miami. Goldfarb has been exclusively practicing endocrine surgery in Los Angeles since 2011. Her expertise is minimally invasive surgery for thyroid cancer and disorders, hyperparathyroidism and adrenal tumors.

In some medical cases, such as cancer, the thyroid is removed. Humans can live without their thyroid if a hormone pill is taken daily.

Promoting good thyroid health

Science tells us that for the thyroid to remain healthy, it needs iodine to produce hormones, but just a little.

"It turns out that one teaspoonful of iodine is enough for a lifetime of thyroid hormone production. But the thyroid gland needs a constant supply of iodine, so we must intake iodine in some form on a daily basis and not all at once," Samet said. Too much iodine can actually make the thyroid produce less hormones.

The best way to get iodine is through eating healthy foods, such as seafood and dairy products. You can also get it by seasoning your food with iodized salt.

Additional resources

Johns Hopkins: Thyroid GlandDigital Journal: Thyroid Gland Disorders Treatment Market- Asia Pacific Increases Thyroid Gland Disorders Treatment Demand, North America Continues to Lead ItFDA: FDA Alerts Veterinarians and Pet Food Manufacturers about Potential Presence of Thyroid Hormones in Pet Foods and TreatsNLM: Metastatic Tumors of the Thyroid Gland