For a relatively tiny part of the body, the thyroid can have a significant health impact.
The butterfly-shaped gland sits at the front of the throat and secretes hormones that play a key role in regulating numerous metabolic processes, including heart rate, weight and body temperature. If a thyroid stops functioning properly it can result in health issues, sometimes serious ones.
In 2004, Caitlin Richards (pictured above, left) had been experiencing bouts of fatigue and fainting, so she booked an appointment with her GP to find out why. One possible cause was immediately evident to her doctor.
“She said, ‘Are you aware you have a goitre?’ I was like, ‘Uh, nope’,” Caitlin recalls.
An ultrasound and blood tests revealed the then-13-year-old had hypothyroidism, or an underactive thyroid. It had been “overworking” to produce the hormone Thyroxine, but hadn’t been successful, thus causing the gland to swell up considerably.
Caitlin Richards (left) as a teenager. (Image supplied)
Hypothyroidism is the most common thyroid problem; research from MedicalDirector's General Practice Research Network suggests it accounts for 70 per cent of thyroid condition medical visits. Interestingly, these conditions affect women more frequently than men.
"For people with hypothyroidism, their low Thyroxine level will make them sluggish and tired most of the time," explains MedicalDirector chief medical officer Dr Andrew Magennis.
"This can be compared with those who have hyperthyroidism, where people can’t sleep and feel constantly agitated or anxious."
Caitlin was initially diagnosed with Hashimoto's disease, an autoimmune condition that commonly causes hypothyroidism.
She began taking daily hormone tablets and was monitored by an endocrinologist every six months, to have her levels checked and medication adjusted accordingly.
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Caitlin says her age made it hard to tell whether the condition produced any symptoms — she remembers being "quite tired" at the time, but points out this isn't uncommon for a teenager so she didn't think much of it.
"I also wasn't overweight, which was unusual because usually with an underactive thyroid you can put on weight. That's never been an area of concern for me," Caitlin, now 26, adds.
Although her Hashimoto's diagnosis changed, she remained on medication for her underactive thyroid until two years ago.
Caitlin made an appointment with her endocrinologist and explained she hadn't been consistent with her medication, but didn't feel as though that had affected her negatively.