House Call: Over- or underactive thyroid can lead to trouble
I once had a patient who was generally a pretty mellow guy. He developed severe hyperthyroidism, became agitated, and got arrested for violent behavior. Once we got his thyroid regulated, he was back to normal.
Your thyroid is one of many glands that make up your endocrine system. Endocrine glands secrete hormones that regulate the daily activities your cells and organs perform to keep your body functioning and healthy. Your thyroid is a small butterfly-shaped gland at the front of your neck, just below your voice box. Unless you are very thin or have a really good imagination, a normal-size thyroid gland is difficult to feel.
Your thyroid produces two biologically active hormones: thyroxine (known as T4) and triiodothyronine (known as T3). T4 has four iodine atoms attached to it; T3 only has three of them. T4 is made exclusively by the thyroid gland and most T3 is made when other organs convert T4 to more active T3 by snipping off an iodine atom. Thyroid hormone preparations most commonly prescribed for an underactive thyroid, hypothyroidism, are the T4 form (known as levothyroxine).
Most table salt has iodine added to it because your thyroid needs it to produce thyroid hormone. When you lack iodine, the thyroid can become enlarged; a very large thyroid is called a goiter. In pregnant women, inadequate iodine and/or thyroid hormone can cause severe problems in brain and body development of their newborns. Before putting iodine in salt, goiters and developmental disability were more common, especially in areas far removed from the ocean (where iodine-rich seafood is less common).
Too much thyroid hormone, hyperthyroidism, is like stepping on the gas pedal while your car is in neutral: The engine runs faster, but you just sit there. Too little hypothyroidism is more like having a compression leak; the engine runs, but power is low.
Hyperthyroidism can cause:
Hot flashes, sweating
Trembling
Weight loss
Diarrhea
Hair loss
Nervousness, irritability, insomnia
Racing heart.
Common symptoms for hypothyroidism include:
Fatigue
Weight gain
Difficulties concentrating, mental slowness and depression
Constipation
Sensitivity to cold
Slow pulse
Waxy skin thickening and swelling
Dry skin
Deep, hoarse voice
Brittle, dry hair
Loss of sexual desire or potency problems.
Reading these symptoms, you may think you have a thyroid problem. Many overlap with other diseases and are common symptoms in general. That’s why it is important that your health care provider gets your health history in detail. Blood tests are the ultimate way to reveal if your thyroid is over- or underactive, but your history contains important information that helps determine the likely cause of your symptoms and needed testing.
Other health issues that can involve your thyroid include inflammation, enlargement, nodules and cancer. It’s important to keep in mind that thyroid lumps or nodules are quite common; only about 5 percent of them turn out to be thyroid cancer. Papillary thyroid cancer, the most common type, carries an excellent prognosis for most people.
The course of action your health care provider recommends depends on how your thyroid is performing, the cause and how much it affects daily activity. Some issues resolve over time and others only need watchful waiting. When treatment is needed, it ranges from medication to control hyper- or hypothyroidism or to treat thyroid cancer; radioactive iodine to treat hyperthyroidism or thyroid cancer; or surgery to remove an enlarged thyroid gland (goiter) that may contain nodules. If you feel you may have a thyroid problem, it’s best to discuss your symptoms and to have an exam with your health care provider.
Dr. Bob Riggs is a family medicine physician practicing at Group Health’s Riverfront Medical Center. His column appears biweekly in Live Well.