Optimal thyroid hormone balance requires diligent monitoring and close management by one’s endocrinologist. Because it is safe and easy to use (typically taken daily), taking a thyroid hormone may seem like a straightforward process. However, much time, planning, and forethought are needed to maintain proper thyroid hormone balance.  

“One of my areas of great interest is thyroid management,” says Robert Constant, M.D., F.A.C.E., a board-certified clinical endocrinologist and hormone specialist at the Diabetes and Endocrine Center of Orlando. “I’m often asked not only by patients but other physicians about the work we have to do to maintain people’s thyroid hormone in very close management.”

What is Hypothyroidism?

Hypothyroidism is defined as the failure of the thyroid gland to produce sufficient thyroid hormone to meet the metabolic demands of the body. The thyroid gland is located at the base of the neck, just below the Adam’s apple.

The butterfly-shaped gland produces thyroid hormone and is responsible for distributing it throughout the body. Thyroid hormone regulates essential organic functions and metabolic processes, including the speed at which you burn calories and the rate of your heartbeat.

Roughly one in 300 people in the United States have hypothyroidism. The disease is most common in women over the age of 60. Hypothyroidism may occur as a result of primary gland failure or insufficient thyroid gland stimulation by the pituitary gland. Autoimmune thyroid disease is the most common cause of hypothyroidism.

Hypothyroidism occurs when too little T3 and T4 hormones are produced, slowing down cell processes. Untreated hypothyroidism can contribute to:

  • Hypertension
  • Dyslipidemia
  • Infertility
  • Cognitive impairment
  • Neuromuscular dysfunction

thyroid-hormone

As the body slows, you may notice that you feel colder, fatigue more easily, have drier skin, become forgetful and depressed, or experience constipation. Because the symptoms are so variable and nonspecific, the only way to know for sure whether you have hypothyroidism is with a simple blood test for TSH.

How is Hypothyroidism Treated?

Hypothyroidism can’t be cured. But in almost every patient, hypothyroidism can be controlled entirely. It is treated by replacing the amount of hormone that your own thyroid can no longer make, to bring your T4 and TSH levels back to normal levels.

“Thyroid hormone is a very safe medication that people typically take just once a day, so patients commonly think that it’s a medicine that is extremely simple to use and to titrate properly,” says Dr. Constant. “However, the thyroid hormone is a medicine with a very narrow therapeutic window, and because of that, it requires careful titration (dosage adjustment). We spend a lot of time and effort trying to make sure that patients have appropriate thyroid levels.”

Synthetic thyroxine pills contain hormones precisely like the T4 that the thyroid gland makes. All hypothyroid patients except those with severe life-threatening hypothyroidism can be treated in the doctor’s office, and not have to be admitted to the hospital. For the few patients who do not feel completely normal taking a synthetic preparation of T4 alone, the addition of T3 (Cytomel®) may be of benefit.

What are the Symptoms of Hypothyroidism?

Hypothyroidism occurs when too little T3 and T4 hormones are produced, slowing down cell processes. Untreated hypothyroidism can contribute to:

  • Hypertension
  • Dyslipidemia
  • Infertility
  • Cognitive impairment
  • Neuromuscular dysfunction

As the body slows, you may notice that you feel colder, fatigue more easily, have drier skin, become forgetful and depressed, or experience constipation. Because the symptoms are so variable and nonspecific, the only way to know for sure whether you have hypothyroidism is with a simple blood test for TSH.

How is Hypothyroidism Treated?

Hypothyroidism can’t be cured. But in almost every patient, hypothyroidism can be controlled entirely. It is treated by replacing the amount of hormone that your own thyroid can no longer make, to bring your T4 and TSH levels back to normal levels.

“Thyroid hormone is a very safe medication that people typically take just once a day, so patients commonly think that it’s a medicine that is extremely simple to use and to titrate properly,” says Dr. Constant. “However, the thyroid hormone is a medicine with a very narrow therapeutic window, and because of that, it requires careful titration (dosage adjustment). We spend a lot of time and effort trying to make sure that patients have appropriate thyroid levels.”

Synthetic thyroxine pills contain hormones precisely like the T4 that the thyroid gland makes. All hypothyroid patients except those with severe life-threatening hypothyroidism can be treated in the doctor’s office, and not have to be admitted to the hospital. For the few patients who do not feel completely normal taking a synthetic preparation of T4 alone, the addition of T3 (Cytomel®) may be of benefit.

Why are There Many Different Doses of Thyroid Hormone?

Thyroid hormone is necessary for the health of all the cells in the body. Therefore, taking thyroid hormone is different from taking other medications, because its job is to replace a hormone that is missing. The only safety concerns about taking thyroid hormones are taking too much or too little.

“It’s one of the reasons why there are so many different doses of thyroid hormone,” says Dr. Constant. “The reason is we have to spend a lot of time making sure that we have people on exactly the right dose.”

When someone begins taking a thyroid hormone, the initial dose is carefully selected based on information such as a person’s weight, age, and other medical conditions. The dose will then need to be adjusted by a physician to keep the thyroid function regular. Your physician will make sure the thyroid hormone dose is correct by performing a physical examination and checking TSH levels.

“Thyroid hormone is a medicine that’s not particularly well-absorbed,” Dr. Constant continues. “Therefore, it’s very important when people have variability in their thyroid levels to make sure they’re taking medicine appropriately so that they absorb it consistently and benefit the most from it. We spend a lot of time counseling patients and making sure they’re on the appropriate kind of medicine and the proper dose in order to give them optimal thyroid control.”