A butterfly-shaped gland positioned around the larynx (aka the voice box), the thyroid gets a lot of attention in midlife. (Feel tired? Maybe it’s your thyroid? Gained weight? Maybe it’s your thyroid. Freezing cold? Probably your thyroid. Sound familiar?) It’s little wonder, though, that we blame it for many of our woes.
As part of the endocrine system, this powerhouse gland generates hormones that influence virtually every organ system, impacting metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood. Overall, one in eight adults develops a thyroid problem in his or her lifetime. Women are more likely than men to have a disorder. But thyroid dysfunction is treatable.
A healthy thyroid produces a steady stream of two hormones — triiodothyronine (T3) and thyroxine (T4) — and it relies on hormones produced by other organs, for example those produced in the brain by the pituitary gland, to direct its work.
Determining if the thyroid is functioning properly is not easy. There are several forms of thyroxine that can have an impact. Four initial blood tests measure them:
- TSH – measures the hormone that is produced in the pituitary gland and stimulates the thyroid.
- T4 – measures circulating thyroxine. There are two tests really: total T4, which is the thyroxine as it is carried in the blood stream; and free T4, which measures the amount of the hormone that is free to be active and is often preferred.
- T3 – measures triiodothyronine, an active component of thyroxine.
- T3RU (aka T3 resin uptake) – measures the binding capacity of a hormone called thyroxin-binding globulin, which gives another picture of activity.
Only an expert in thyroid problems can interpret these tests.
Diagnosis of a thyroid disorder often occurs very late, as many of the symptoms of thyroid disease are nonspecific. In other words, tiredness, hair loss, weight loss, or weight gain are easily attributed to other things. And according to endocrinologist and Harvard Medical School associate professor Dr. Jeffrey Garber, women over 60 especially “… generally have more nonspecific symptoms [so] doctors may not think to test for [thyroid disease].”
Concerned about your thyroid function? Ask your doctor to assess you.
A diagnosis of hypothyroidism means your gland is underactive and not producing enough thyroid hormone. Symptoms include:
- Unusual fatigue
- Mood swings
- Unexplained weight gain
- Change in voice (such as persistent hoarseness)
- Inability to tolerate cold
- Coarsening of the hair, skin, and nails
- Heavy, infrequent periods
The most common cause of hypothyroidism is a result of a condition called Hashimoto’s thyroiditis. Women are at least eight times more likely to get Hashimoto’s than men, and it’s most prevalent in women ages 40 to 60. The disease strikes when your body’s own immune system attacks your thyroid gland. At the beginning of the disease, the thyroid produces too much hormone. Over time there is irreversible damage to the gland, which results in reduced hormone production. Though medication cannot cure Hashimoto’s, a daily dose of thyroxine will help keep a healthy level of thyroxine in your body.
If hypothyroidism disorders go untreated, a woman’s chances of developing high cholesterol, high blood pressure, and heart disease can increase. Symptoms of menopause may be worse, and research shows that treating hypothyroidism with medication can reduce or alleviate some menopause issues.
Less common than hypothyroidism, hyperthyroidism is an overactive gland producing too much hormone. There are a few causes:
- Thyroiditis – an inflamed thyroid gland leaks hormones into the blood, as is the case with Hashimoto’s
- Thyroid nodules – lumps grow in the thyroid, causing hormone overproduction
- Graves’ disease – the most common form of hyperthyroidism affects 70 percent of people; a genetic autoimmune condition tricks the thyroid into overworking.
- Unexplained weight loss
- Disturbed sleep or insomnia
- Vision problems
- Rapid or irregular heart rate
- Feeling too hot when others are comfortable
- Increased appetite
Long-term symptoms for Graves’ disease are bulging, red, or swollen eyes; sensitivity to light; and blurring or double vision.
Hyperthyroidism also impacts the body’s ability to use calcium, contributing to bone loss, fractures, and osteoporosis. That’s especially concerning for women over 50, half of whom are already experiencing bone loss. Therefore, hyperthyroidism should not go untreated.
Antithyroid medications and radioactive iodine can slow the production of thyroid hormones, but in some cases, surgery may be necessary to remove all or part of the gland.
Photo: Antonio Diaz