Thyroid disease: Women are 5 times more likely to get it than men - here's how to spot the signs
A malfunctioning thyroid is a more common problem than you might think, especially among women, with hyperthyroidism afflicting younger women more. Here, doctors explain thyroid disorder, what the symptoms are and its treatment options.
Five years ago, when she was a 21-year-old student, Lee Mun Ling came down with a niggling flu that wouldn’t go away – a rare occurrence as she seldom fell sick.
At the hospital, the doctors suspected dengue fever and so a blood test was carried out. The results were negative for dengue, but they uncovered other problems.
For one, her blood pressure was sky-high even though she had no heart disease. Also, her heart rate was through the roof. Alarmed, the doctors put her in the trauma ward and performed more tests.
Lee said: “Eventually, they told me I had hyperthyroid caused by Graves’ disease, an autoimmune condition.”
After two years of daily oral medication to control her over-active thyroid, she was healthy for a year. But then she had a relapse.
“The medication failed to fix the problem the second time round. And so the doctors suggested radioactive iodine treatment, which is basically to kill the thyroid gland,” she said.
WHAT IS THYROID DISORDER?
Dr Kathleen Sek, an endocrinology consultant with National University Hospital as well as the Fast and Chronic programmes at Alexandra Hospital, explained that the thyroid gland is a butterfly-shaped organ located at the base of the neck. It makes, stores and releases thyroid hormones into the blood, hence regulating metabolism.
“Thyroid hormones influence how fast the body produces and uses energy. Your brain, heart, blood vessels, liver, muscles, skin and reproductive system all require thyroid hormones to function normally,” she said.
A disorder can occur when there is an abnormality in the gland’s structure, such as a growth, or in the amount of hormones it secretes.
Though thyroid disorder can take different forms, Dr Sek said the two most common ones are hyperthyroidism – where the thyroid gland releases too much thyroid hormones – and hypothyroidism, where it doesn’t produce enough of it.
Between the two types of disorders, she felt hypothyroidism is likely more common – an observation shared by Dr Adoree Lim, an endocrinology consultant at Singapore General Hospital.
“We do not have local data on the prevalence of all thyroid conditions in Singapore. However, we expect them to be similar to that in many other parts of the world,” said Dr Lim.
In the United States, said Dr Sek, it is estimated that 1.2 per cent of the population have hyperthyroidism, while up to 5 per cent have hypothyroidism.
THE CAUSES OF THYROID DISORDER
There are various triggers for thyroid disorder, the most common of which, said Dr Sek, are autoimmune disorders.
“Autoimmune disorders occur when the immune system produces antibodies against normal tissue in the body. It is not known why this happens, but there appears to be a genetic link, and thyroid disorders commonly run in the family,” she said.
Dr Lim explained that hypothyroidism is often due to the autoimmune disorder known as Hashimoto’s disease, while hyperthyroidism results from Graves’ disease.
She said: “With Hashimoto’s disease, antibodies produced by our own white blood cells target the thyroid gland, gradually destroying its ability to produce thyroid hormone.
“As for Grave’s disease, the antibodies overstimulate the thyroid gland, causing it to produce too much thyroid hormone.”
WOMEN ARE MORE AT RISK: THYROID DISEASE SYMPTOMS TO WATCH FOR
Although thyroid conditions can occur in both men and women of all ages, Dr Sek said women are five times more likely to get thyroid disorders compared to men. In addition, hyperthyroidism more commonly afflicts younger women.
Signs of hyperthyroidism include weight loss despite a good appetite, often feeling hot or anxious, a fast pulse, tremors, and frequent bowel movements.
Baddariah binte Mohd Karim, a 42-year-old mother-of-three, recounted experiencing these exact symptoms barely a year after the birth of her third child.
“My hands trembled all the time, I was sweating a lot, passing motion often and losing weight. Because my heart was beating so fast, I had difficulty sleeping, which then resulted in fatigue. When my blood test results came back, they showed my thyroid level was seven times higher than normal,” she said.
Hypothyroidism has the opposite symptoms. The body’s metabolism slows down and individuals may put on weight despite a reduced appetite, feel cold and tired, or be constipated. They may also experience dry skin, hair loss and leg cramps.
In addition to all the above symptoms, which are common to both genders, Dr Sek said women may also experience abnormal menstrual periods, have difficulty conceiving or have recurrent miscarriages.
You may also notice swelling or a lump in your neck, which could be a sign of both hyper- and hypothyroidism – although doctors would also look out for other symptoms such as tremors, and weight and appetite changes in the diagnosis.
However, Dr Lim noted that many of these signs are not specific to thyroid disorder and may be experienced by otherwise normal individuals.
“The best way to diagnose both hyper- and hypothyroidism is by performing a blood test which measures the levels of the thyroid hormone and the antibody known as TSH (thyroid stimulating hormone),” she advised.
Such was the case for 44-year-old Celine Tan, who had a bout of mild hypothyroidism in her early twenties.
“I was lethargic and had slight hair thinning and weight gain. But the symptoms were mild so it was almost impossible to guess the problem. They were also very generic and could be due to other ailments,” she said.
Thinking it wasn’t serious, she didn’t see a doctor.
“It was only when I was in Canada for a student exchange that I went to the university doctors because I was feeling so out of sorts. They quickly diagnosed that I had thyroid issues,” said Tan.
HOW THYROID DISEASE IS TREATED
Dr Lim said there are three main ways of treating hyperthyroidism: Oral medication, radioactive iodine (RAI) therapy, or thyroid surgery. All three methods work to decrease the production of thyroid hormones.
She elaborated: “During RAI therapy, a small dose of radioactive iodine is ingested and absorbed by thyroid cells – the only cells in our body that take up iodine. The radioactivity destroys the thyroid cells slowly over time.”
Thyroid surgery involves removing most of the thyroid gland. Dr Lim explained that the treatment is recommended if the swelling of the gland is big and cosmetically unattractive for the patient. It is also used if there is a concern about cancer in the thyroid.
For hypothyroidism, patients are treated with supplements of the thyroid hormone, thyroxine.
“This is given as a small pill daily, has very few side effects and almost no allergic reactions. Once the dose of thyroxine you require has been established, it is usually stable for life except during pregnancy,” she said.
As low levels of thyroid hormone during pregnancy may harm the baby or cause miscarriages, the doctor will have to adjust the dosage of thyroxine.
THYROID DISORDER TREAMENT: KNOCK-ON EFFECTS AND IMPLICATIONS
Both Dr Sek and Dr Lim said that adverse effects from anti-thyroid medication are rare, though not unheard of. But it is long-term or untreated thyroid disorders that are the real causes for concern.
“Untreated hyperthyroidism can cause abnormal heart rhythms such as fast, irregular heart rate, heart failure in the long run, or a severe, dangerous form of hyperthyroidism known as a thyroid storm. It can also worsen osteoporosis,” said Dr Lim.
For women planning to have children, Dr Sek emphasised that it is essential to ensure normal thyroid function prior to conceiving.
She warned: “Poorly controlled maternal hyperthyroidism is associated with miscarriage, pregnancy-induced hypertension, prematurity, low birth weight, intrauterine growth restriction, stillbirth, thyroid storm and maternal heart failure.”
Maternal hypothyroidism, too, needs to be well managed, she added. “Otherwise, it has been linked to an increased risk of adverse pregnancy complications, such as premature birth, low birth weight, pregnancy loss and lower offspring intelligence quotient.”
Even RAI treatment and thyroid surgery, while seeming to nip the problem of hyperthyroidism once and for all, can have wider implications.
Dr Lim said both these treatments carry the risk of causing hypothyroidism instead.
“This happens because too many thyroid cells are destroyed or most of the gland is removed, so there is insufficient thyroid hormone produced,” she explained.
Although she said hypothyroidism is easily diagnosed and treated with thyroid hormone replacement, some patients do report difficulties during their adjustment period.
Baddariah said her metabolism became very low after RAI treatment, causing her to feel sluggish easily. She also experienced brain fog and mood swings.
Similarly, Lee said she felt unmotivated and had no energy to carry out many normal activities, while her yoyo-ing weight added to feelings of mild depression.
“Although the doctors did advise me of the potential side effects, I had a hard time adjusting after undergoing RAI therapy. I was under the impression the side effects would be mild, but they turned out more severe than I expected,” she said.
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