Tiredness a sign of thyroid trouble
If you’ve been feeling sluggish for ages and can’t figure out why, you could be one of the 2 per cent of people who have an underactive thyroid gland. The thyroid is located in our neck, just below the Adam’s apple, and it plays an essential role in maintaining our bodily functions. The thyroid uses iodine to manufacture two hormones – known as thyroxine (T4) and triiodothyronine (T3).
T4 and T3 are released into the blood stream in response to a surge of TSH (thyroid stimulating hormone), a hormone produced in the pituitary gland in the brain, and circulate round the body regulating our metabolism.
Disorders of the thyroid gland are surprisingly common, but typically are quite insidious in nature – this means the symptoms, although often eventually very impacting, can come on slowly and mimic lots of other conditions.
Patients will often describe having had symptoms for years, but explaining them away with ‘‘I’m just tired, or unfit’’. In those situations, diagnosis and treatment often brings huge relief and a renewed energy for life.
There are two main types of thyroid disorder – underactivity, known as hypothyroidism, and overactivity, known as hyperthyroidism. The following relates to hypothyroidism, which is the more common of the two.
Women are around 10 times more likely than men to suffer from an underactive thyroid and, although it can come on during childhood (and rarely be present from birth), it gets much more common as we age.
Aside from being female, and ageing, the other risk factors for developing an underactive thyroid include:
■ Iodine deficiency In certain parts of the world (especially in developing countries) this is incredibly common, and globally is the biggest cause of thyroid disease.
■ Living or being born in Japan Japanese people have higher rates of autoimmune thyroid disease.
■ Having Down syndrome (Trisomy 21) or Turner syndrome.
■ Being on certain medications These include amiodarone (a blood pressure medication), lithium (a mood stabiliser) and drugs used to treat thyroid overactivity.
■ Being pregnant Around 2.5 per cent of women will develop an underactive thyroid while they are pregnant, and even greater numbers will have a transient episode of ‘‘underactivity’’ in the six months after their baby is born. These don’t all go on to become permanent thyroid problems but can mean you are at increased risk of this in the future.
■ Having certain other ‘‘autoimmune’’ conditions These include vitiligo, diabetes, coeliac, pernicious anaemia or Addison’s disease.
Although tiredness seems to be almost universal in people with an underactive thyroid, the other symptoms can vary a lot. They include:
■ Weight gain and fluid retention
■ Constipation
■ Dry skin and hair
■ General body aches
■ Feeling cold
■ Mental ‘‘slowing down’’, which can include poor memory and impaired concentration, especially in elderly people
■ Irregular or heavy periods
■ Loss of libido
■ Infertility
■ Low mood and even for some people, depression
■ Carpal tunnel syndrome (numbness, pain and tingling in the hands, particularly at night).
Although only a tiny number of people in New Zealand are born with hypothyroidism, this is a common way for it to present in less developed countries, particularly where there is a high prevalence of iodine deficiency.
As our rates of iodine are pretty good, we don’t tend to see this here, but do see lots of hypothyroidism resulting from other causes in older people. The most common causes include:
■ Autoimmune thyroiditis In this condition, our body starts to develop antibodies against the thyroid gland which gradually destroy it, rendering it underactive, and eventually inactive if left untreated. This condition is linked to other autoimmune conditions, as mentioned previously. If it is associated with a goitre (a swelling of the thyroid gland that is often visible to the naked eye), it is called Hashimoto’s thyroiditis.
■ ‘‘Latrogenic’’ hypothyroidism This includes a range of things that can permanently damage the thyroid gland and impair its function, for example, radiotherapy, surgery or radio-iodine treatment (used to treat an overactive thyroid). Certain drugs, as already mentioned, can also impact on the functioning of the thyroid gland.
■ Infiltration of the thyroid This can occur in conditions like amyloidosis and sarcoidosis.
■ ‘‘Secondary’’ causes of hypothyroidism These
include things that affect the pituitary in the brain (and hence interrupt the production of thyroidstimulating hormone) such as tumours, radiation therapy or infection.
If you are concerned that you may have one or more of these symptoms and it’s not improving with time, please consider asking your doctor for a thyroid blood test.
This is such a simple check to do and will give you an answer within a few days. It’s far better to know about a thyroid issue early on, than suffer from symptoms for years before finding out, by which stage it will be harder to reverse the damage to your body. If left untreated, people with underactive thyroid issues are at higher risk of heart disease and elevated cholesterol levels.
Depending on the cause of your thyroid problem, your doctor may suggest some more tests (such as an ultrasound scan or needle biopsy if you have a goitre), and occasionally might recommend you see a hormone specialist, known as an endocrinologist. However, for the majority of uncomplicated cases, treatment simply involves topping up your thyroxine levels with a synthetic version of T4.
Typically, the dose needs to be gradually titrated upwards, guided by regular blood tests, but once you are on a stable dose, you will likely remain on this for life.
From a doctor’s point of view, detecting and treating hypothyroidism is one of the more rewarding things we get to do.
People genuinely feel so much better on treatment and, sadly, that’s not always the case with other health issues.