The thyroid is a tiny gland located in your neck that produces hormones responsible for regulating everything from metabolism to muscle control. Despite its small size, this little gland can be troublesome if it doesn't function properly.
Thyroid disease can manifest as either an underactive thyroid gland (hypothyroidism) or an overactive thyroid gland (hyperthyroidism) and cause a range of symptoms. However, most of these signs are subjective, making the condition impossible to diagnose without a blood test.
But if you've ever found yourself feeling exhausted, gaining weight or feeling a little blue you may have wondered (especially after googling your symptoms) whether you might have thyroid disease. We explore some surprising facts about the condition.
It probably isn't causing your weight gain
You'll often find an underactive thyroid gland (hypothyroidism) cited as a cause of weight gain. However, whilst in extreme cases this condition can lead those affected to put on a few more pounds, it's more likely that weight gain - even in someone with the condition - is down to a number of different factors.
"For the majority of cases of hypothyroidism, which are rather mild, treating it doesn’t affect weight particularly; it's only in the most severe cases."
"Weight gain has a number of causes," agrees Dr Bernard Khoo, consultant endocrinologist at The London Clinic. "It's multifactorial. It's partly due to what people eat; partly it's our activity levels; partly it's something that you inherit from your parents. It could also be to do with gut bacteria; research suggests if you have a low population you can start gaining weight. Finally, poor sleep also plays a part in weight gain."
It could send you into a tailspin
When an overactive thyroid gland spins out of control, it can sometimes send those affected into a spiral of anxiety.
"When you have an overactive thyroid gland it increases your stress hormones (like adrenaline) and their effect on the body. Your thyroid basically makes the adrenaline more effective; you get a higher heart rate, palpitations and become sweatier," explains Khoo.
"The problem is that if you get anything that worries you at all, it causes the heart rate to go up far more than it would if your thyroid gland were normal. You feel it, then you feel more worried and this can go round and round - sending you into a tailspin of anxiety and sometimes panic attacks."
"Conversely, when someone has a really underactive thyroid gland then it can be a bit like depression - the patient becomes less interested in life, they feel tired and don't sleep properly," he adds.
It might lead to unusual hair loss
Whilst both underactive and overactive thyroid conditions can lead to hair loss from the head, an underactive thyroid gland may also cause sufferers to shed hair from their eyebrows.
"The outer part of the eyebrows can become thin in people with thyroid underactivity," explains Pearce. "Usually people notice hair loss from the head, but not many patients come to seek help for their eyebrows." However, this hair loss is a fairly common symptom of the condition.
It can affect your thinking
If you're suffering from thyroid disease, you may find it affects the way you think.
"Those who suffer from an underactive thyroid gland often complain about not being able to think straight or that they have 'brain fog'," explains Khoo.
But the problem isn’t confined to those with an underactive thyroid gland.
"In contrast, people with overactive thyroid glands say they can have quite a short attention span and be a bit snappy," adds Pearce.
Many of us have unnoticed goitres
One of the more obvious symptoms of thyroid dysfunction is a lump in the neck, caused by swelling of the thyroid gland, known as a goitre. Whilst this can be a sign of cancer, "99% of the time, these growths are benign," according to Khoo.
However, surprisingly many of us have a goitre without knowing.
"If you were to scan people on the street, 50% of women and about 30% of men will have a thyroid lump," explains Khoo. "Most of the time people don't even notice or feel these growths."
It might masquerade as pregnancy or menopause
However, thyroid problems can disrupt the menstrual cycle. Sufferers of an underactive thyroid gland may have heavy, prolonged periods; and those with an overactive thyroid gland may find their periods become very light or stop completely.
"Problems with menstruation can come on gradually," points out Pearce. "For example, often women will notice menstrual disturbance for a while before they completely stop."
The medication might not resolve your symptoms
We're all looking for a magic pill to help us to control our weight, make us feel more alert and stabilise our emotions. But unfortunately, even if your weight problems or tiredness are caused by a thyroid disorder, medication won't necessarily provide the answer.
Although thyroid disease may be a piece of the puzzle, it's likely that it is not the butterfly-shaped gland in isolation causing your health concerns.
"Quite often the symptoms don't just have one cause. Sometimes it's multifactorial," explains Khoo. "Although a lot of people come to us with a symptom, believing it to be caused by their thyroid disease, quite often the problem may be caused by a patient's lifestyle."
You probably don't have it
You may well have a number of symptoms connected with thyroid disease, but according to the British Thyroid Foundation in the UK only 5% of people have the condition.
The issue with the disease is that many related symptoms are more likely to have a different cause.
"Usually, with all the various symptoms, thyroid is towards the bottom of the list of possible causes," explains Khoo. "In fact, the vast majority of people who believe they have an underactive thyroid because of something they've read on the internet won't have the condition."
The only conclusive test for this condition is a blood test, so if you are concerned, speak with your GP to see whether your symptoms warrant additional investigation.