Hello, in this HealthSketch we’d like to talk to you about thyroid disorders,
which are conditions of the thyroid gland. Thyroid disorders can affect anyone:
men, women and children, but they are more common in women, and become more common with age.
The thyroid gland is a small butterfly-shaped organ that is found in the neck just in front
of the voice box. It makes the thyroid hormones, T3 and T4,
which act as chemical ‘messengers’, travelling through the blood stream to all the cells and
tissues in the body. These thyroid hormones control the speed at which your body works,
which is also called your body’s ‘metabolism’. They therefore affect your heartbeat,
energy levels, digestion, body temperature, and even how you think and feel. For such a small
gland, which many people haven’t heard of, it has a huge effect on how our bodies work!
Because of this, it is important to have the right amount of thyroid hormones in the body:
if there is too little then the cells work too slowly, but if there is too much,
the cells work too quickly. The brain helps to keep levels in check by measuring the
levels of thyroid hormones in the blood. If levels are low, the pituitary gland releases
Thyroid Stimulating Hormone, or ‘TSH’, to stimulate the thyroid gland to release more
thyroid hormones. If thyroid hormone levels are too high, then less TSH is released by the brain.
In this way, the levels of thyroid hormones in the blood are usually kept in balance.
However, in some people, the thyroid gland doesn’t work properly.
An underactive thyroid gland can lead to too little thyroid hormone being made,
which is called hypothyroidism (because hypo means ‘too little’). Others can have
an overactive thyroid gland, where thyroid hormone levels are too high, which is called
hyperthyroidism (because hyper means ‘too much’). These are the two main types of thyroid disorder.
The symptoms of hypo and hyperthyroidism are very wide-ranging:
In hypothyroidism, the body’s metabolism slows down. This can lead to symptoms such as tiredness;
weight gain; feeling cold; constipation; dry or thinning hair; muscle weakness and aches;
a hoarse voice; ‘pins and needles’ in the hands; slow speech, movements and thoughts;
low mood and anxiety; memory problems; and concentration problems. In babies and children,
hypothyroidism can also affect normal growth and development if not treated properly.
In hyperthyroidism, by contrast, the body’s metabolism speeds up.
This leads to a very different pattern of symptoms, such as: a racing heartbeat;
loss of weight; feeling sweaty and shaky; feeling uncomfortably hot; diarrhoea; thirst; itchiness;
mood swings; feeling anxious and irritable; concentration problems; and restlessness.
While these symptoms are wide ranging, it is rare to experience all of them, and they may be
missed or confused with other conditions. For some people, symptoms are subtle and hardly noticeable,
while for others, they can have a significant impact on daily life. Depending on the cause,
symptoms may come on quickly over a matter of days, or slowly over many months or years.
Thyroid disorders may also have other effects, such as: a swollen thyroid gland (known as a
‘goitre’), nodules or lumps on the thyroid, and eye problems (which are most likely to
affect people with an overactive thyroid and are sometimes called ‘thyroid eye disease’).
Uncontrolled thyroid disorders can also lead to problems with fertility and pregnancy,
and long-term heart problems. Therefore, it is important to get a diagnosis,
even if symptoms are mild.
Thyroid disorders are diagnosed by checking the levels of thyroid hormones in the blood
and sometimes by a physical examination. Usually, in hypothyroidism, TSH will be
high and T4 will be low, and in hyperthyroidism, TSH will be low and T4 will be high. Depending
on your diagnosis there may be further investigations, such as follow up blood tests,
and possibly a thyroid scan or biopsy, to find out the underlying cause.
So, what are these underlying causes of thyroid disorders?
• Rarely, hypothyroidism can be present at birth, when babies are born with a thyroid gland
that does not develop or work properly. This is called congenital hypothyroidism, and all babies
receive a blood spot test at birth to screen for this, so it is almost always picked up early.
• Thyroid disorders can also be acquired at any age throughout life,
including childhood, through a range of causes: o Of these, autoimmune causes are the most common:
like with other autoimmune conditions, the body’s own immune system is the problem,
creating antibodies that either attack or stimulate the thyroid gland. Hypothyroidism
is usually caused by Hashimoto’s disease and hyperthyroidism is most commonly caused by Graves’
disease. Both of these can run in families. o Thyroid nodules: are extra lumps or
nodules of thyroid tissue, which are usually benign (or non-cancerous)
but they can affect thyroid hormone levels. Very rarely these nodules will be cancerous which will
require specialist treatment. o Iodine deficiency: which is
more common in the developing world. o Other rarer causes of thyroiditis:
such as after an infection, after pregnancy, or with certain medications such as lithium
and amiodarone. These are usually temporary. o Problems with the pituitary gland in the brain.
o And as a consequence or side effect of thyroid treatment.
So how are thyroid disorders treated? The main aim of treatment is to ensure the right levels of
thyroid hormones in the blood. If levels are too low, then synthetic thyroid hormone medication can
be taken as a replacement. If levels are too high, antithyroid medication can be taken to dampen down
the overactivity of the thyroid gland. Apart from medication, treatment for an overactive thyroid
can also include taking a radioiodine capsule, which targets thyroid tissue, or surgery to
remove some or all of the thyroid gland, which may also be recommended for a goitre or for nodules.
Replacement medication may be needed after these treatments.
Whatever the treatment, and even if no treatment is currently needed,
it is important to have regular blood tests so that your doctor can monitor your thyroid function
and adjust dosage if needed. This monitoring is particularly important during pregnancy.
So, what can you do to improve your condition? It is important to take medication regularly as
prescribed, for example, on an empty stomach at the same time each day.
Leading a healthy lifestyle is recommended, such as having a well-balanced diet and
stopping smoking. This is especially important with hyperthyroidism and thyroid eye disease.
Smokers are much more likely to develop thyroid eye disease than non-smokers.
Living with a thyroid condition can also affect your mood and sense of wellbeing,
and it can help to talk about this with your doctor, friends and family.
Many find it helpful to join patient support groups, to connect with others who are going
through similar experiences. While these can be lifelong conditions, symptoms usually respond well
to treatment, and so most people with thyroid disorders will lead normal and healthy lives.
We hope this HealthSketch has been helpful to you and those around you.