SAYS THE DOC:

A little background: The thyroid is a gland in the neck that produces thyroid hormones, which have a strong influence on all aspects of metabolism — such as heart rate, body temperature, and the rate at which the body burns fat. If a person’s thyroid produces too much hormone, he or she is hyperthyroid, with a metabolic rate above normal; if it produces too little hormone, he or she is hypothyroid, with a below-normal metabolic rate. The conditions are two sides of a coin, and produce opposite symptoms.

Graves’ Disease is the leading cause of hyperthyroidism — which is what Aryeh was originally diagnosed with. It’s an autoimmune disorder wherein antibodies override the feedback loop that normally regulates the thyroid’s production of hormones (see sidebar), causing the thyroid to produce an overabundance of hormones. This puts the metabolism into overdrive, which can result in weight loss, palpitations, shakiness, excessive sweating, and anxiety. Graves’ is most often diagnosed in women under 40, and there’s a strong genetic component. About one third of patients present with exophthalmos, a condition which causes red, bulging eyes.

What caused Aryeh’s blackouts? “People with hyperthyroidism have an elevated heart rate at rest, and intense exercise can raise the rate to such a high level that their blood pressure drops and they black out,” explains Dr. John C. Morris, an endocrinologist at Mayo Clinic in Rochester, Minnesota.

The radioactive iodine treatment that Aryeh underwent is the most common treatment for hyperthyroidism in the U.S. Sometimes, the thyroid is removed. Both of these treatments usually result in permanent hypothyroidism. There are also drug therapies that impair the thyroid’s ability to produce hormones, but they cannot be taken long-term due to serious side effects, and only about one third of patients stay in remission once off the drugs. Those who relapse will need radioactive iodine treatment or to have their thyroid removed.

Hypothyroidism: A Thyroid Self-Destructs

“I was 26 years old, blessed with two children, and eagerly looking forward to another pregnancy, which I assumed would happen as quickly as it did the first two times,” Henny says. “Yet the months wore on and I was still eating for one. Not that my figure stayed svelte — I was slowly morphing from thin to undeniably chubby. After a year, I realized two things, although I didn’t connect them at the time: I had gained a whopping 30 pounds, and I had an infertility problem.

“I blamed the weight gain on my unaccommodating genes, and went to a reproductive endocrinologist to get help with the fertility issue,” Henny continues. “The sonogram showed that I wasn’t ovulating, and there were cysts on my ovaries which indicated either PCOS (polycystic ovarian syndrome, an endocrine disorder) or hypothyroidism. Bloodwork confirmed that I indeed had hypothyroidism, yet it wasn’t clear that I didn’t also have PCOS. Both conditions can halt ovulation, and knowing how eager I was to become pregnant, my doctor treated me for both.

“Within a few weeks, I had dropped 15 pounds and was expecting. It was only after I became pregnant with my fourth child, a few short months after delivering my third — while on Synthroid for my thyroid condition, but no treatment for PCOS — that we knew it was the thyroid condition that explained my infertility, not PCOS.

“In retrospect, I experienced other symptoms of hypothyroidism before I was diagnosed. I was frequently tired, had dry skin, and my hair was falling out. Yet everyone complains of these things, and I had no idea that my case was different.”

SAYS THE DOC:

Henny was diagnosed with Hashimoto’s Disease, an autoimmune disorder that causes inflammation and eventual destruction of thyroid tissue, resulting in an underproduction of thyroid hormones (hypothyroidism). Hashimoto’s accounts for 90% of cases of hypothyroidism in the U.S., occurring most often in middle-aged women. Removal of the thyroid gland (to treat cancer or an overactive thyroid) will also result in hypothyroidism, as will radiation treatment to the head and neck (when treating lymphoma or an overactive thyroid).

It’s not uncommon for women to discover they have a thyroid problem only when they have a hard time getting pregnant, as Henny did. Inadequate thyroid hormone can impair ovulation, leading to infertility. Other common symptoms include fatigue, weight gain, hair loss, feeling cold, joint and muscle pain, slowed thinking, mood swings, and depression.

Because the symptoms can be so wide-ranging and easily attributed to the ups and downs of life — as in Henny’s case — the disease can go undiagnosed for years, until symptoms become more pronounced. Yet even with mild symptoms, it’s important to get a diagnosis because untreated hypothyroidism can lead to complications such as high cholesterol, high blood pressure, heart disease, and goiter (an enlarged thyroid gland that can be unsightly and interfere with breathing and swallowing). A pregnant woman with untreated hypothyroidism has four times the average risk for miscarriage. The potential complications don’t stop there: severe, long-untreated hypothyroidism can result in myxedema, which can be fatal.

Hypothyroidism can cause havoc throughout the body, but thankfully there’s an easy fix: hormone replacement therapy. “Patients simply take a daily pill of synthetic hormone [called levothyroxine, brand name Synthroid] and within a few weeks their thyroid hormone levels are usually back to normal, and symptoms should resolve,” says Dr. Morris. “Levothyroxine will need to be taken for the rest of their lives.

“It’s important to understand that although hormone levels in the blood are normal when on the pill, in Hashimoto’s, the underlying autoimmune disorder is still there, and the thyroid gland continues to be attacked. Over time, the thyroid produces diminishing levels of hormones, so the dosage of levothyroxine will usually need to be increased.”

Chagit, a 34-year-old mother of five, was diagnosed with Hashimoto’s a few years ago and put on levothyroxine. “The medication lessens my symptoms somewhat, but my thyroid problems persist,” she maintains. “I still have a very hard time losing weight, I’m always tired, and often moody and anxious.”

Complaints about weight are pretty typical, according to Dr. Robert McConnell, professor of medicine at Columbia University Medical Center in New York. But they’re not well-founded. “Chagit is subscribing to a common misunderstanding,” Dr. McConnell explains. “People with hypothyroidism often blame their weight on their condition, but if they’re on the correct dosage of hormones, their weight troubles are unrelated to their thyroid. Seventy-five percent of a person’s weight is determined by genetics, and thyroid function is only one of the many inputs that influences metabolism.”

Because of this widespread misperception about hormone replacement, healthy people will sometimes ask Dr. Morris for a levothyroxine prescription, thinking it will help them shed pounds. “While it’s true that it would increase their metabolic rate and may cause weight loss,” Dr. Morris says, “I counsel them that they’d be making themselves very unhealthy in the process. Excess hormones can cause bone thinning, muscle weakness, and disrupt their cardiac rhythm, among other things.”

It’s also common to blame one’s thyroid for fatigue, but if a patient with hypothyroid is on the correct dosage of hormones, the complaints are generally due to other factors. In the case of Chagit, for instance, she has a baby who is often up during the night — and that’s likely the real reason for her exhaustion.

All in the Family

“The summer I was 15, I went for a routine physical exam and discovered that my blood pressure was through roof,” Daniel remembers. “I was put on medication, but other strange things began happening to me. Over the course of the summer, I lost 30 pounds, and my heart was continuously racing. At first I attributed this to how active I was being, but then I started having dizzy spells, and even blacking out while exercising.

“When I was diagnosed with hyperthyroidism, I joined the family club: my mother has hypothyroidism, and my cousin has hyperthyroidism. I underwent radioactive iodine treatment, went on Synthroid, and my life was back. A number of years later, I married Tova.”

In her youth, Tova had also developed thyroid issues. “I’m one of triplet sisters. When I was ten, I began to steadily gain weight, while my sisters, who had the same eating habits, stayed thin,” Tova relays. “My grandfather and mother both have Hashimoto’s, so when my bloodwork showed that I, too, had the disorder, I’m sure no one was shocked.

“I married Daniel and we have three kids. Because of the strong family history, last year we had our oldest daughter Shulamis, who was 5 at the time, tested. Lo and behold, she, too, has hypothyroidism. She was treated for a few months, and once her hormone levels were back to normal, the doctor took her off the drugs since the potential side effects on such young children is unknown. So far, her levels have stayed normal off the medicine. While things look good now, we don’t know how this will play out.”

SAYS THE DOC:

There’s a strong tendency for thyroid dysfunction to run in families. Yet Daniel’s mother is hypothyroid — is that related to his hyperthyroidism? “Genetically speaking, it’s one and the same,” Dr. McConnell says. “Daniel and his mother have different manifestations of a basic autoimmune thyroid disorder. It’s common for family members to have alternate forms of the disorder.”

Even with a strong genetic predisposition, thyroid disorders usually don’t declare themselves until adulthood, but it can happen at any age, as it did with Shulamis. In fact, a baby can be born without a thyroid gland and be perfectly healthy, as long as he’s treated with levothyroxine right away.

Infants with untreated hypothyroidism are often sleepy, jaundiced, have poor muscle tone, and puffy faces; if left untreated, there will be severe physical and mental retardation. These days, hospitals routinely screen newborns for congenital hypothyroidism.

Why did Shulamis’ hypothyroidism seem to disappear? “First of all, there are transient forms of hypothyroidism, such as due to a virus, which we can’t rule out for Shulamis,” says Dr. McConnell. “But with her strong family history, the disorder will likely re-manifest itself at some point. The more likely explanation for her remission is that all autoimmunity has a tendency to wax and wane.”

Postpartum Thyroiditis

“After I had my first child, I felt very unwell,” Aliza, 32, describes. “I was always tired, my throat hurt constantly, the glands in my neck were bulging, my eyes were bulging. My weight dropped to a skeletal 95 pounds, 15 pounds below my pre-pregnancy weight. I was freaked out and depressed — what was happening to me?

“A few months and some blood tests later, I was diagnosed with both hyperthyroidism and mononucleosis. My doctor told me that thyroid problems aren’t unusual after birth, and very often go away on their own. I breathed a huge sigh of relief when mine did, a few months later.

“My second child was born a few months after that,” Aliza continues, “and this time I felt so sluggish afterwards that I could barely move. Naps were as essential to my day as eating lunch. This time — surprise! — I was diagnosed with hypothyroidism. I never do the same thing twice! I started hormone replacement therapy, and my hormone levels stabilized. Nine years later, I’m still hypothyroid, but my levels remain normal on levothyroxine.”

SAYS THE DOC:

Aliza’s case is demonstrative of how, in medicine, things often don’t fit into clearly labeled boxes. After her first pregnancy, she displayed symptoms of both an overactive thyroid (bulging eyes, weight loss, and anxiety) and an underactive thyroid (fatigue and depression).

In this case, the paradox was solved with a few simple blood tests: she did have hyperthyroidism, which was caused by postpartum thyroiditis. But the fatigue (and swollen glands and throat pain) was explained with a diagnosis of mono. As for the depression, perhaps it was postpartum, perhaps it was due to her feeling so ill and not knowing why. (Some speculate that postpartum thyroiditis may explain many cases of postpartum depression, so new mothers with depressive symptoms would be wise to have their thyroid function tested.)

Postpartum thyroiditis refers to any inflammation of the thyroid gland after birth — whether from hyper- or hypothyroidism. It occurs in up to 10% of postpartum women, and can present in three different ways: a period of hyperthyroidism followed by a period of hypothyroidism, or hyper- or hypothyroidism alone. All of these forms most often resolve by 12-18 months after delivery, but up to around 25% of those with postpartum hypothyroidism will remain hypothyroid for the rest of their lives. That Aliza experienced a different form after each birth isn’t strange, as all forms are believed to be part of the same underlying autoimmune disorder.

Aliza describes how each time she’s pregnant, her Synthroid dosage is increased. Why? “In a normal pregnancy, a mother will produce around 50% more thyroid hormones than usual, to meet the needs of both her own body and her fetus,” explains Dr. McConnell. “First dibs on hormones goes to the fetus. If the mother is hypothyroid, her own levels will drop as the fetus absorbs the scantly available hormones, and she’ll need a higher dosage of replacement hormone.”

When It’s Cancer

Sara, 50: “When I was 38, I went for a routine mammogram/breast ultrasound. For no other reason than ‘why not?’ The doctor moved the ultrasound probe to my neck to peek at my thyroid. She didn’t like what she saw. This surprised me because I had just been to the internist, who palpated my thyroid and tested my hormone levels, and everything seemed normal. My doctor was on to something, though, because the biopsy revealed cancer. My thyroid was removed, followed by radioactive iodine treatment. Today I’m on Synthroid and everything is fine.”

Riki, 55: “About 15 years ago, I went to my gynecologist for a routine exam and she felt a bulge on my neck that concerned her. Follow-up testing found a malignant tumor. My thyroid was removed, making me instantly hypothyroid; I’ll be on Synthroid the rest of my life. I also had a course of radioactive iodine treatment to destroy any thyroid cells that may have been left.”

SAYS THE DOC:

“Until recently, thyroid cancer was most often found as a palpable, sometimes visible lump in the neck, as in Riki’s case,” Dr. Morris says. “Today, with the amount of imaging done for all sorts of things, it is probably most often found incidentally on a chest CT scan, carotid artery ultrasound, MRI of the neck, or another test.”

Fortunately, thyroid cancer is one the most curable cancers, and the survival rate is extremely high. And, unlike other cancers, a spread to the lymph nodes doesn’t decrease survival rates. Thyroid cancer spreads to distant locations in just 5% of cases (typically bones and lung), but even these patients tend to do well. While often there are no symptoms, one can feel hoarse or have difficulty breathing or swallowing. Standard treatment is to remove most or all of the thyroid; this is often followed by radioactive iodine treatment.

THE BODY’S THYROID THERMOSTAT

To ensure there is a just-right amount of thyroid hormone in the body at all times, the thyroid and brain communicate constantly via a feedback loop. When levels of thyroid hormone in the blood drop, receptors on the cells of two brain structures — the hypothalamus and the pituitary — detect the change. To correct the imbalance, the hypothalamus will release a hormone called TRH, which stimulates the pituitary to release another hormone, TSH. Its job is to stimulate the thyroid to increase production of thyroid hormones.

As hormone levels rise, the hypothalamus and pituitary again detect the change, and decrease production of TSH and TRH, leading to a reduction of thyroid hormones. This sensitive feedback loop, analogous to a thermostat, allows thyroid hormones to stay at healthy levels.

Doctors typically look at TSH levels in the blood to determine if a patient has a thyroid problem. High levels of TSH in a patient’s blood sample mean the thyroid isn’t producing enough hormone, indicative of hypothyroidism. Low levels of TSH mean the thyroid is producing too much hormone, indicative of hyperthyroidism.

(Originally featured in Family First, Issue 475)