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Your Thyroid: What It Does and Why It Matters

This short guide explains what your thyroid does, how to spot when something might be wrong, and when it is time to see your GP.

By Nick Buete
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What Is the Thyroid?

The thyroid is a small, butterfly-shaped gland that sits at the front of your neck, just below your Adam's apple.

Despite its small size, the thyroid has a big job: it produces hormones that control how your body uses energy.

Think of the thyroid as your body's internal thermostat and speedometer. It helps regulate:

  • How fast your heart beats

  • How quickly you burn calories

  • How warm or cold you feel

  • How well your brain concentrates

  • How your digestive system moves

The Two Main Thyroid Hormones

Your thyroid makes two key hormones:

  1. T4 (thyroxine) – the main hormone your thyroid releases into the blood

  2. T3 (triiodothyronine) – the active form that your cells actually use

Most T3 comes from converting T4 in organs like the liver and kidneys.

Your brain controls thyroid hormone levels through a feedback loop:

  • The hypothalamus (in the brain) sends a signal

  • The pituitary gland (also in the brain) releases TSH (thyroid-stimulating hormone)

  • TSH tells the thyroid how much hormone to produce

When everything is working well, this system keeps your hormone levels balanced.

What Happens When the Thyroid Isn't Working Properly?

There are two main problems that can occur:

1. Underactive Thyroid (Hypothyroidism)

This means your thyroid is not making enough hormones.

Common symptoms include:

  • Feeling tired all the time

  • Unexplained weight gain

  • Feeling cold, especially in your hands and feet

  • Dry skin and hair

  • Constipation

  • Low mood

  • Brain fog or poor concentration

  • Heavy or irregular periods (in women)

2. Overactive Thyroid (Hyperthyroidism)

This means your thyroid is making too much hormone.

Common symptoms include:

  • Feeling anxious or restless

  • Unexplained weight loss

  • Feeling hot and sweaty

  • Fast or irregular heartbeat

  • Trembling hands

  • Trouble sleeping

  • Frequent bowel motions or diarrhoea

Who Is at Risk?

Thyroid problems are common in Australia, especially in women.

You may be at higher risk if:

  • You are female (women are 5–8 times more likely to develop thyroid problems)

  • You are over 40

  • You have a family history of thyroid disease

  • You have other autoimmune conditions (such as type 1 diabetes or coeliac disease)

  • You are pregnant or have recently given birth

  • You have had thyroid surgery or radiation to the neck

When Should You See Your GP?

If you have been experiencing any of the symptoms listed above for more than a few weeks, it is worth booking an appointment with your GP.

Your doctor can:

  • Talk through your symptoms

  • Examine your neck to check for thyroid swelling

  • Order a simple blood test to check your thyroid hormone levels (TSH, T4, and sometimes T3)

  • Refer you to a specialist (endocrinologist) if needed

Important: Do not ignore ongoing fatigue, unexplained weight changes, or heart palpitations. Early diagnosis makes treatment much more effective.

How Are Thyroid Problems Treated?

For Underactive Thyroid

Most people take a daily thyroid hormone tablet (usually levothyroxine, a synthetic form of T4).

  • Treatment is usually lifelong

  • Regular blood tests help your doctor adjust the dose

  • Most people feel much better within a few weeks to months

In some cases, your doctor may prescribe a compounded thyroid medicine if:

  • You need a specific dose not available commercially

  • You have allergies or intolerances to certain ingredients

  • Your doctor recommends a combination of T4 and T3

For Overactive Thyroid

Treatment depends on the cause and may include:

  • Medicine to reduce hormone production

  • Radioactive iodine treatment

  • Surgery (in some cases)

  • Medicine to manage heart rate or anxiety

Simple Ways to Support Your Thyroid

While thyroid conditions usually need medical treatment, lifestyle choices can help support overall thyroid health:

1. Eat a Balanced Diet

  • Include foods rich in iodine (seafood, dairy, iodised salt)

  • Get enough selenium (Brazil nuts, eggs, fish) and zinc (meat, legumes, seeds)

  • Eat plenty of vegetables, whole grains, and lean protein

Note: In Australia, iodine deficiency is uncommon but can still occur, especially during pregnancy.

2. Manage Stress

Chronic stress can affect thyroid function over time. Helpful strategies include:

  • Regular physical activity (walking, swimming, yoga)

  • Relaxation practices (deep breathing, meditation)

  • Good sleep habits

3. Avoid Smoking

Smoking can worsen thyroid problems and increase the risk of thyroid eye disease.

4. Get Regular Check-Ups

If you have a thyroid condition, regular blood tests and GP visits help ensure your treatment is working well.

Key Takeaways

  • The thyroid is a small gland that controls how your body uses energy

  • Thyroid problems are common, especially in women over 40

  • Symptoms can be vague (fatigue, weight changes, mood changes), so it is easy to dismiss them

  • A simple blood test can diagnose most thyroid problems

  • Treatment is usually straightforward and very effective

  • If you have ongoing symptoms, see your GP – do not wait

Trusted Australian Resources

For more information about thyroid health:

If you have questions about thyroid health or compounded thyroid medicines, speak with your GP or contact Gardens Compounding Pharmacy.

Notice to the reader

Educational only — not medical advice.

This article is reviewed by the dispensary team but isn't a substitute for professional medical advice. Speak with your prescriber before starting, altering, or stopping any treatment.