What you need to know about your thyroid gland

When Sandra Hebert was eight years old, her family knew something was wrong. “I was lethargic, overweight, had dry scaly skin and my hair was dull and falling out.” This was 1953, and her doctor was stumped. It was her mom’s brother who recognized the signs of hypothyroidism (when the thyroid gland produces too little hormone).

To have your thyroid monitored in the 1950s was a traumatic process, just shy of torture, with barbaric-looking machines and retesting every three months. These days it’s as simple as a blood test, which is good because about 10 percent of Canadians suffer from a thyroid condition, and women are at a much greater risk than men.

Thyroid problems are often hereditary, but like in Hebert’s day, doctors and patients still have trouble recognizing the symptoms. They’re often mistaken as depression, anxiety or stress. But what’s actually happening is that the body is producing either too much or too little of the thyroid hormones — thyroxine (T4) and triiodothyronine (T3) — which help manage moods, weight and energy levels. Patients diagnosed with a malfunctioning thyroid are given medication and are retested regularly to ensure the dosage is aligned with the body’s fluctuating hormones — especially during puberty, pregnancy and menopause. The signs and symptoms for hyper- and hypothyroidisms couldn’t be more different. “I know people with hyper who can’t sit still,” says Herbert, “and people with hypo who can sit still for a long, long time.”

Hypothyroidism Most patients with hypothyroidism — when the thyroid doesn’t produce enough hormones — experience extreme tiredness, dry skin and hair and weight gain. Some find a lump in their neck, often due to the swelling of the thyroid gland. It’s also difficult to get pregnant if you have an untreated thyroid issue. Vanessa McHugh suffers from hypothyroidsm — and is on a synthetic hormone-replacement drug. As long as the dosage is correct, there are no side effects and most people are able to lead a symptom-free life.

But McHugh still struggles, even when blood tests show her levels are normal. She experiences body aches, tiredness, night sweats and difficulty losing weight. “I basically have to stay on a 1,200-calorie per day diet and work out five days a week.” And after having difficulty conceiving, McHugh is now pregnant with twins and has to be closely monitored. “In the first trimester, the embryo doesn’t have its own thyroid,” says endocrinologist Wendy Rosenthall, “and is totally relying on the mother’s thyroid hormone. If the mother’s hormone level is really low in the first trimester, there’s a potential concern that the brain development of the fetus won’t be normal.” According to Rosenthall, patients who know they are hypothyroid should have their dos- ages adjusted and monitored during pregnancy, which will hopefully prevent thyroid-related complications for mother and baby.

The big concern, says Rosenthall, is helping people figure out there’s a problem in the first place. “If you have a family history of it, if you see a lump in your neck, or something seems suspicious: ‘I’m having trouble getting pregnant and by the way, I’ve been gaining weight and have been tired all year,’ then your thyroid should be checked.”

Hyperthyroidism Hyperthyroidism — when the thyroid produces too much of the hormones — is less common but it has much more striking features. Patients often complain that their heart rate is going up, or skipping a beat. “They lose weight, or eat whatever they want and don’t gain,” says Rosenthall. “They feel hot, shaky and jittery.” Hyperthyroidism causes bone mineral loss in the body, which leads to osteoporosis; and with the heart beating so fast and working so hard, sufferers are at risk of angina or heart failure.

One treatment for hyperthyroidism is a drug that suppresses the excess hormones. It has potential mild side effects like a skin rash and joint pain. But some people experience a more serious side effect called agranulocytosis — which is the loss of white blood cells, making the body prone to infection. In those instances, a different treatment is needed. The other options include eradicating the malfunctioning thyroid with radioactive iodine or taking out the gland. In these two cases, the patient usually becomes hypothyroid and takes the hormone supplement for the rest of her life.

Melanie Reis-Guaragna, 30, was experiencing insomnia, anxiousness, extended menstrual periods, breast tenderness and had lost 20 pounds in three months before she was diagnosed with hyperthyroidism and was put on medication. Her condition was stabilizing, but when she got pregnant everything changed again. She became hypothyroid during pregnancy — which happens, but is rare — and had to be put on medication to boost her hormone levels. After giving birth, her levels fluctuated between being hyper to hypo. “It’s been a roller coaster ride,” she says.

Women who have had a baby can also develop postpartum thyroiditis within the first year after childbirth. A painless inflammation of the thyroid gland, the symptoms start out looking like hyperthyroidsim but later resemble hypothyroidism. It’s often temporary, and if mild requires no treatment. But for some it turns into a long-term hypothyroidism condition requiring hormone replacement. While there are no known causes, women with immune disorders or type 1 diabetes are more at risk. For thyroid patients, there’s no cure. Rather, it’s a lifelong process of finding and keeping the right hormonal balance through medication.

What about kid control? When Guylaine Pichette’s second son, Anthony, was born, he was listless and wouldn’t latch on her breast. “I knew something was wrong,” she says, and she suspected congenital hypothyroidism since her firstborn, Xavier, and her husband were also born with it. She was right; Anthony was born without a properly functioning thyroid. The condition, which affects about one in every 2,500 newborns, is difficult to diagnose because the symptoms — constipation, jaundice and sluggishness — are very non-specific in a baby, says Guy Van Vliet, an endocrinologist at Montreal’s CHU Sainte-Justine Research Centre.

When untreated, congenital hypothyroidism leads to irreversible brain damage. But thanks to the late Quebec doctor Jean Dussault, newborns in the Western world are now screened through the routine heel-prick blood test taken during their first couple days of life — and are able to start treatment (a daily tablet of hormone replacement) right away.

Hypo- or hyperthyroidism can also develop in kids between the ages of 10 and 15. Julie Wong was diagnosed with hypothyroidism at 11. “I was feeing really lethargic,” she says. “I had dry hair and skin but I also had eczema, so it was hard to tell what was hypothyroidism and what was the other condition. And I had this lump in my throat.”

Wong’s mother and grandmother had thyroid conditions and knew what to look for. Wong, now 16, has been on hormone medication for the past five years — and gets her TSH levels checked regularly. If the dosage is off, she’ll feel tired and cold all the time. But with a small tweak to her medication, she’ll be stabilized again. “The good thing about hypothyroidism,” she says, “is that once you’ve got it diagnosed it’s not at all scary. It’s easy to manage – not some big weight you have to lug around for the rest of your life.”

A version of this article appeared in our May 2012 issue, with the headline The Super Gland (p. 47).