Thyroid disease: Causes, symptoms and treatments
Thyroid disease is an umbrella term used to describe conditions affecting your thyroid, such as hyperthyroidism and hypothyroidism.
As part of the endocrine system, your thyroid produces hormones that not only control the speed of your metabolism, but regulate your temperature, breathing, heart rate, digestion and skin and bone health.
If you develop thyroid disease, your body starts producing either too many or not enough thyroid hormones, resulting in a range of health problems.
In this article, we explore what thyroid disease is, the types of thyroid disorders you can develop, thyroid disease symptoms and treatments available.
When functioning regularly, your thyroid produces a range of hormones, such as thyroxine (T4) and triiodothyronine (T3), to control your metabolism and regulate other bodily functions.
With thyroid disease, your thyroid no longer produces the right amount of thyroid hormones, leading to either hypothyroidism or hyperthyroidism. In some cases, you can develop both hypothyroidism and hyperthyroidism at different times in your life.
What is hypothyroidism?
Otherwise known as an underactive thyroid, hypothyroidism is where your thyroid doesn’t make enough hormones, causing your metabolism to slow down.
While most common in women over 60, hypothyroidism can affect anyone of any age, sex or ethnicity.
Hypothyroidism symptoms
Symptoms of hypothyroidism include:
- Anxiety
- Brain fog
- Depression
- Dry skin and hair
- Fatigue
- Muscle aches
- Numbness or tingling in your hands
- Sensitivity to cold
- Weight gain
What is hyperthyroidism?
Hyperthyroidism, also known as an overactive thyroid or thyrotoxicosis, occurs when your thyroid gland produces more hormones than your body needs. The main hormones made in excess are triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH).
The condition can affect anyone, but is around 10 times more common in women than men, and typically affects people between 20 and 40 years of age. You might also be more prone to developing hyperthyroidism if you have a family history of thyroid disease, are a smoker, and are pregnant.
Hyperthyroidism symptoms
- Difficulty sleeping
- Diarrhoea
- Feeling nervous, anxious or irritable
- Hair loss
- Increased heart rate or blood pressure
- Sensitivity to heat
- Weight loss
- A goitre, or a swelling in your neck as your thyroid gland becomes enlarged
Symptoms of hyperthyroidism can start suddenly or develop gradually over time.
What causes hypothyroidism?
Hashimoto’s disease
Hashimoto's thyroiditis, or Hashimoto’s disease, is an autoimmune disease that attacks your thyroid.
You’re more likely to develop Hashimoto’s disease if you:
- Are a woman
- Are middle aged
- Have a family member with Hashimoto’s thyroiditis
- Have other autoimmune diseases, such as rheumatoid arthritis, Addison disease and type 1 diabetes
Previous thyroid treatment
Hypothyroidism can occur as a result of previous thyroid gland treatment, such as thyroid surgery or radioactive iodine therapy.Iodine deficiency
Iodine is a trace element found in fish, milk and other dairy products, and is a key component in the production of thyroxine.
While rare in the UK, a deficiency in this mineral can result in your thyroid underproducing this hormone, leading to hypothyroidism.
Congenital hypothyroidism
Congenital hypothyroidism, or CHT, describes hypothyroidism that’s present at birth, with the baby being born with an absent or underdeveloped thyroid (dysgenesis), or a thyroid that cannot make thyroid hormones (dyshormonogenesis).
Symptoms of the disorder include sleepiness, difficulty feeding, and jaundice, yet as babies are tested for CHT five days after birth, most infants with the condition are diagnosed before symptoms start to show.
Pituitary hypothyroidism (secondary hypothyroidism)
This is a condition where your pituitary gland doesn’t make enough thyroid-stimulating hormone (TSH) for your thyroid to produce hormones.
Pituitary hypothyroidism can be present at birth, or may develop later due to a pituitary tumour, a medical condition such as Sheehan syndrome, radiotherapy or certain medications
What causes hyperthyroidism?
Graves’ disease
Graves’ disease is a chronic autoimmune disorder where your immune system attacks your thyroid gland, causing it to produce excessive hormones. While it’s the most common cause of hyperthyroidism, it’s still relatively rare amongst the general population.
The disease mostly affects people assigned female at birth, and while it typically occurs in people aged between 30 and 50, it can affect children and older adults, too.
You’re also more likely to develop Graves’ disease if you have a family history of thyroid’s disease, are a smoker, and have another autoimmune disease, such as rheumatoid arthritis, lupus and vitiligo.
Excessive iodine
Certain medications, such as amiodarone, can cause too much iodine to build up in your body, triggering excessive hormone production.Pituitary adenoma
A pituitary adenoma is a benign or non-cancerous tumour in the pituitary gland, a small gland at the base of your brain. Some pituitary adenomas secrete too much thyroid-stimulating hormone (TSH), causing your thyroid to produce excessive hormones and leading to hyperthyroidism.
Thyroid cancer
Thyroid cancer is a rare type of cancer that affects the thyroid gland. This cancer can alter the production of thyroid hormones, leading to hyperthyroidism.Medications
Some medications, such as lithium, amiodarone and interferons, can cause thyroid problems.
Thyroid nodules
Thyroid nodules are a common occurrence where abnormal lumps, otherwise known as growths, develop on your thyroid gland. They are almost always non-cancerous, but may lead to an overactive or underactive thyroid.Thyroiditis
Thyroiditis is inflammation of your thyroid gland. It usually causes temporary hyperthyroidism, followed by temporary or chronic hypothyroidism.
The condition can have several causes, such as autoimmune disorders, viral infections (subacute thyroiditis), and childbirth (postpartum thyroiditis).
What are the risk factors for thyroid disease?
Anyone can develop thyroid disease, but you may have a higher risk of developing problems with your thyroid if you:
- Are female
- Are over 60 years of age
- Have a family history of thyroid disease
- Have an autoimmune disease such as pernicious anaemia, type 1 diabetes, rheumatoid arthritis or lupus
- Have had radiotherapy to your head or neck
- Have Turner syndrome
- Take medication high in iodine
- Don’t get sufficient iodine in your diet
How is thyroid disease diagnosed?
To diagnose thyroid disease, your consultant will ask about your symptoms, medical history and any medications you are taking. They’ll feel your thyroid gland to check for abnormalities, such as an enlarged thyroid gland or thyroid nodules.
If they suspect you have thyroid disease, your consultant will order a thyroid function test, a blood test that checks the levels of thyroid hormones in your blood. In some cases, they may refer you for an imaging scan, such as a thyroid ultrasound, to check for thyroid nodules or a swollen thyroid.
How is thyroid disease treated?
Treatment for thyroid disease depends on the thyroid disorder you have and the cause behind it.
Treatment for hyperthyroidism
Hyperthyroidism can be treated with medication, radioactive iodine therapy, thyroid surgery or a combination.
Medication
To treat hyperthyroidism, you may be prescribed a thionamide, a medication that stops your thyroid from overproducing hormones.
Thionamide can take a few months to work, and may need to be taken for 12 to 18 months. Once your thyroid hormone levels are back to normal, your medication can be gradually reduced or stopped, but depending on your circumstances you may need to take them for a longer term or for life.
Your consultant may also prescribe beta-blockers to help with symptoms of hyperthyroidism, such as a fast heart rate.
Radioactive iodine therapy
Radioactive iodine therapy is a type of radiotherapy that damages the cells in your thyroid, stopping it from producing excessive hormones. It may be recommended when medication hasn’t worked.
During the treatment, you’ll take medication containing iodine before being given a low dose of radiotherapy that is absorbed by your thyroid.
As radioactive iodine therapy may take weeks or months to take effect, you may need to take medication in the meantime.
Surgery
Thyroid surgery, or a thyroidectomy, involves removing all or part of your thyroid gland, and offers a permanent cure for hyperthyroidism as you’ll no longer produce any thyroid hormones.
After your surgery, you’ll need to take synthetic thyroid hormone tablets for the rest of your life.
Treatment for hypothyroidism
Synthetic hormone replacement medication is the main treatment for an underactive thyroid, with a daily tablet called levothyroxine often prescribed.
To ensure you’re getting the right dosage, you’ll undergo regular blood tests to check your thyroid hormone levels .
It can take a while to find the correct dose of levothyroxine for you, and you’ll need to have regular blood tests to check your thyroid hormone levels until the right dose is reached. Once you’re taking the correct dose, your consultant will normally check your hormone levels once a year.
If your blood tests show that you have hypothyroidism, but you have mild or no symptoms, your consultant may choose to monitor your hormone levels every few months, delaying treatment until you develop symptoms.
Can thyroid disease be prevented?
Most cases of thyroid disease are caused by genetics, or autoimmune disorders and cannot be prevented. If your thyroid disease is related to too much or not enough iodine in your body, you can increase the amount of iodine in your diet to increase the production of thyroid hormones in your body.
Is thyroid disease a serious illness?
Thyroid disease is a common and usually manageable condition, but untreated thyroid disease can lead to complications.
Complications of hyperthyroidism include:
- Atrial fibrillation
- Osteoporosis
- Stroke
- Heart failure
Complications of hypothyroidism include:
- Depression
- Coronary artery disease
- Infertility
- Peripheral neuropathy
Untreated or poorly managed hypothyroidism can result in a rare, but life-threatening condition called myxoedema coma (myxoedema crisis), that can lead to coma and, if untreated, death.
Get help with Circle Health Group
Thyroid disease is usually a chronic condition that needs lifelong management, yet it’s perfectly possible to live a normal life with the right treatment and support.
At Circle Health Group we offer a range of treatment options for thyroid disease, including hyperthyroidism treatment, hypothyroidism treatment, radioactive iodine treatment and thyroid surgery.
If you would like to learn more about our treatment options, book your appointment online today or call a member of our team directly on 0808 189 4921.
Clinical sources
- Underactive thyroid (hypothyroidism), NHS
- Overactive thyroid (hyperthyroidism), NHS
- Thyroid Disease, Cleveland Clinic
- Thyroid Disorders, John Hopkins Medicine
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