Your Thyroid Is Your Metabolic Control Center | Ascension

Your Thyroid Is Your Metabolic Control Center

Your thyroid controls the rate that every cell and organ turns nutrients into energy. If your thyroid doesn’t work properly – neither do you.

Located just under your Adam’s apple, your thyroid secretes hormones into the blood stream to control the rate that every cell and organ turns nutrients into energy.

Thyroid hormones control metabolism, growth, body temperature, muscle strength, appetite, and the health of your heart, brain, kidneys, and reproductive system.

Thyroid cells are the only cells in the body that absorb iodine. The thyroid uses iodine to create the T4 (thyroxine) and T3 (triiodothyronine) hormones. The thyroid responds to the levels of Thyroid Stimulating Hormone (TSH) secreted by the brain’s pituitary gland. As the TSH levels in the blood rise, the thyroid responds by making more hormone; as the levels drop, the thyroid is signaled to make less hormone.If your thyroid doesn’t work properly – neither do you.

When things go wrong

Thyroid disease occurs when your thyroid under- or over-produces the correct amount of thyroid hormone. It can cause elevated cholesterol levels, heart disease, infertility, muscle weakness, osteoporosis, coma, and even death. Thyroid disease can be hereditary.

Thyroid diseases

Hypothyroidism occurs when the thyroid gland fails to produce enough hormone. The most common cause of hypothyroidism is the autoimmune disease Hashimoto’s thyroiditis. Autoimmune diseases cause a person’s body to attack its own tissue as if it were a foreign substance. An estimated one in 50 women suffer hypothyroidism. This number increases to 17 percent of women and 9 percent of men over age 60.

Symptoms may include constant fatigue, forgetfulness, intolerance of cold, loss of appetite, slowed thinking, weight gain, slow pulse, depression, dry skin or hair, brittle fingernails, hair loss, mood swings, hoarse voice, constipation, joint pain, longer and heavier menstrual periods, high cholesterol, and carpal tunnel syndrome. “Hypothyroidism may develop over several years, so people may consider the symptoms are normal,” said Andrew Braun, MD, internal medicine physician with Ascension Medical Group in Stevens Point.

Hypothyroidism also affects children. One in 5,000 babies born in the USA experiences slowed growth, sluggishness, pallor, dry and itchy scalp, sensitivity to cold and constipation due to hypothyroidism.

Goiter is a general term for thyroid swelling. It may develop in a person with hypothyroidism as the gland works harder to produce more hormone.

Thyrotoxicosis is caused by too much thyroid hormone in the blood. Often, this condition is referred to as hyperthyroidism.

Common symptoms of hyperthyroidism include: excess thirst, increased appetite, heat intolerance, exhaustion, shaking, nervousness, jitters, irritability, increased perspiration, weight loss, racing or irregular heartbeat, changes in vision, hand tremors, muscle weaknesses, sleep disturbances, diarrhea or frequent bowel movements, eye problems, lighter menstrual periods, infertility, and generalized itching.

Hyperthyroidism also may cause depression and heart failure. Hyperthyroidism can be treated with medication, radioactive iodine (radioiodine ablation), or by surgical removal of the thyroid (thyroidectomy).

Treatment of hyperthyroidism often causes hypothyroidism at some point in a person’s life.

Grave’s disease is an autoimmune disease that causes hyperthyroidism. In addition to typical symptoms of hyperthyroidism, Grave’s disease may cause inflammation of the eyes, swelling of the eye tissue, and bulging eyes. Grave’s disease can be treated with medication.

Thyroiditis is an inflammation of the thyroid, which may be painful or cause no pain at all. It may cause the thyroid to overproduce hormone.

Thyroid nodules are abnormal masses or lumps in the thyroid gland that may cause hyperthyroidism. Thyroid nodules are often noticed visually or through touch; they are common and are rarely cancerous. Nodules may occur due to iodine deficiency. Nodules can either be surgically removed or destroyed with radioiodine ablation.

While thyroid disease can affect anyone ...

  • 8 out of 10 people with thyroid disease are women
  • 20 percent of people with diabetes are likely to develop thyroid disease

Who’s at risk?

Thyroid cancer often does not cause symptoms. Thyroid cancer is most common in people with a family history of the disease, those who have been exposed to thyroid gland radiation, or people who are over 40 years old.

Thyroid disease manifests itself in subtle ways in older patients. In addition to mild evidence of common symptoms of hypothyroidism, older people may suffer from heart failure, constipation or diarrhea, joint pain, muscle pain, psychosis, dementia, or unsteadiness while walking.

Hyperthyroidism often presents symptoms similar to diseases of the bowel, heart or nervous system. If older people have close family members with thyroid disease, they should be tested.

Thyroid, metabolism and weight

Since the thyroid gland regulates metabolism, there is a strong correlation between thyroid disease and weight. Weight gain is more severe in people with hypothyroidism due to an excess accumulation of salt and water; weight loss is common in people who have hyperthyroidism.

Though it seems that thyroid hormones could be an easy cure-all for weight control, the use of the hormone would also cause loss of muscle protein, which would be detrimental to a person’s overall health.

Are you getting too much iodine?

Too much iodine can worsen both hyperthyroidism and hypothyroidism. The recommended daily allowance of iodine for adults is 150 – 299 micrograms per day.

Iodine-rich foods include:

  • Iodized table salt
  • Seafood
  • Meat / Eggs
  • Bread
  • Milk / Yogurt
  • Strawberries
  • Multivitamins 


Tests for thyroid conditions include blood tests for TSH, T3 and T4 hormones; ultrasounds to check for abnormal tissue; and scans of the thyroid infused with radioactive iodine. CT, MRI, and PET scans, along with tissue biopsies, are used to diagnose cancer.

A radioiodine uptake test measures how well your thyroid absorbs iodine. A small amount of radioactive iodine is ingested. Since the thyroid is the only organ to absorb iodine, the radioactivity locates itself in the thyroid. The thyroid can then be scanned via X-ray.


Hyper- or hypothyroidism can be treated with medication. “Too much thyroid hormone can cause osteoporosis and atrial fibrillation,” said Dr. Braun. “It is important to prescribe the correct amount.”

Is it menopause or thyroid disease?

Thyroid disease strikes one in eight women between the ages of 35 and 65 and one in five women over 65 years of age. Often it goes undetected because it mimics menopausal symptoms. According to the American Association of Clinic Endocrinologists (AACE), women with unresolved menopausal-like symptoms may be suffering from hypothyroidism.

“Non-specific symptoms like exhaustion, brain fog, poor memory, lethargy, mood changes, changes in energy, skin changes, changes in hair texture, hair loss, changes in libido, sleep disturbances, increased nervousness, heart palpitations, irregular or missed periods, depression, and anxiety are common to menopause,” said Dr. Braun.

“Without a blood test, it is difficult to determine the true cause of symptoms.” Neck pain, swelling of arms and
legs, loss of hair from eyelashes or eyebrows, and weight fluctuations are more likely related to thyroid problems.

Hot flashes and night sweats are more likely related to menopause.

Thyroid disease is treatable. If you suffer from any of the symptoms described here, contact your health care provider or find a doctor to find an endocrinologist who can diagnose and treat your symptoms.