The thyroid is a small, butterfly-shaped organ located in the upper part of the neck, near the voice box. For such a small organ, weighing just a few ounces, it has a big impact on the overall health and functioning of many systems in the body. Rich in blood vessels, a healthy thyroid is usually brownish-red and is responsible for producing thyroid hormones and regulating vocal cords' health. A poorly performing thyroid, however, can cause severe health issues.
The thyroid gland consists of two larger lobes. These lobes, in turn, are made up of many smaller lobules, each containing tiny capsules that store thyroid hormones. The thyroid secretes these hormones as needed into the bloodstream to regulate energy levels, metabolism, growth, and development, and body temperature. While a properly functioning thyroid is important for everybody, it's especially essential for growing children and teens.
The thyroid sends signals to the body to grow; specifically, to produce more skeletal and muscle cells. It also is responsible for the onset of puberty -- it adjusts male- and female-specific hormones to prompt and guide the develop secondary sex characteristics. In women, the thyroid also determines menarche and the onset of menopause. The gland aids in metabolizing food and affects energy levels -- a sluggish thyroid slows metabolism. The thyroid also balances hormone levels.
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The thyroid produces three hormones that affect the expression and function of other hormones in the body. Thyroid hormones are known as T3, T4, and Calcitonin. They are formed in the thyroid but need iodine (gleaned from diet) to develop fully. T3 and T4 control metabolism -- the "engine" -- with help from the pituitary gland, which signals how much T3 and T4 to release into the bloodstream.
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Thyroid hormones ensure a steady pulse and help the blood flow smoothly throughout the body by relaxing the blood vessels. A well-functioning thyroid can contribute to lower, healthy blood pressure, a stronger heart, and the ability to pump blood faster when needed, during exercise or in stressful situations. The thyroid also helps keep cholesterol levels in check. An underperforming thyroid, one that doesn't produce enough T3 and T4, can lead to fluid build-up around the heart.
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The thyroid hormones work in partnership with estrogen in women, regulating the menstrual cycle. Uneven levels of thyroid hormones can lead to irregular periods or an inability to ovulate. Thyroid hormones also help signal body changes when conception occurs, preparing women to carry and nourish a fetus. The thyroid hormones responsible for ensuring proper growth and development in children are the same ones that regulate the growth and development of the fetus - a healthy thyroid is essential to reducing the risk of a miscarriage.
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The Thyroid Stimulating Hormone helps growing children, teens, and even babies in the womb grow bone tissue at a healthy rate and replenish old tissue. Thyroid hormones regulate the rate that bone tissue is broken down - if they're too high, the tissue breaks down faster than it can be replaced, leading to osteoporosis and brittle bones. Proper estrogen levels, which the gland also regulates, can help women, especially older adults past menopause, mitigate or avoid osteoporosis.
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The thyroid helps grow and produce other parts of the body, as well, including hair, skin cells, and nails. Healthy thyroids regulate the rate that the skin is renewed, prompting the dead skin cells to shed at a normal pace to maintain firm, smooth skin. The thyroid also facilitates the shedding of dead hair. Slower-acting thyroids retard this process, causing dull and dry skin from a build-up of dead cells. Nails can become dry and cracked, as well.
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Metabolism is essentially the speed at which the body processes energy and distributes it. The faster a metabolism, the more "fuel," in the form of food calories, one needs to maintain a healthy weight and keep each organ network running smoothly; slower metabolisms require less fuel. The thyroid is a primary manager of the metabolism engine. Excess T3 and T4 hormones cause all the cells to work harder, raising the metabolism, while lower-than-normal T3 and T4 production slows down the entire body.
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While some thyroid conditions are a function of genetics or a health condition, thyroid health can be ensured or enhanced in many ways. A body mass index (BMI) in the healthy range for both men and women, as well as moderate exercise, helps keep the thyroid healthy; those with a BMI over 40 are far more likely to have a slower-functioning thyroid. Proper amounts of iodine in the body are also necessary, as the thyroid can't produce hormones without it. Iron and zinc are also critical to the proper production of thyroid hormones. Finally, managing stress levels and balancing estrogen levels (in women) contribute to overall thyroid health.
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Hypothyroidism is the term for a slower-performing thyroid. This can decrease metabolism and cause chronic fatigue. A person may receive a diagnosis of hyperthyroidism if his thyroid produces too many T3 and T4 hormones; this leads to other hormone imbalances and a faster metabolism, sometimes causing rapid weight loss. Goiters are swollen thyroids, a painful condition that not only affects the thyroid itself but also the voice box and blood flow around the neck. Cancer of the thyroid is another disorder that can mimic hypothyroidism.
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