You may have heard the thyroid mentioned during a conversation about energy, weight or blood tests. Knowing a few basic terms can make that conversation less confusing.
Where is the thyroid?
The thyroid is a small gland at the front of your neck. It produces hormones called thyroxine, or T4, and triiodothyronine, or T3. These help regulate how your body uses energy and maintains its temperature. Healthdirect — Thyroid gland.
The pituitary gland sends a signal called thyroid-stimulating hormone, or TSH, which helps control thyroid hormone production. That is why TSH often appears on a thyroid blood-test report. Healthdirect — Thyroid function tests.
What do underactive and overactive mean?
An underactive thyroid makes too little thyroid hormone. An overactive thyroid makes too much. Possible symptoms differ: an underactive thyroid may involve tiredness, constipation or feeling cold, while an overactive thyroid may involve feeling hot, a racing heartbeat or weight loss. Healthdirect — Thyroid gland.
A symptom list is not a diagnosis. Your doctor can consider your history and arrange appropriate tests if a thyroid problem is suspected. Healthdirect — Thyroid gland.
What could you ask your GP?
Start with the change that is bothering you most. Write down when it began, whether it comes and goes, and what you would like to understand.
You might ask: “Could this relate to my thyroid?”, “What else should we consider?” or “What would the test result change?”
Our thyroid-testing guide explains how to prepare for that discussion. Bring your questions even if you are unsure whether thyroid testing is the right next step.
Sources
Read 15 October 2026. Sources support the adjacent general information; clinic links verify appointment descriptions only.
- Healthdirect — Thyroid gland — Australian public-health guidance; accessed 2026-10-15.
- Healthdirect — Thyroid function tests — Australian public-health guidance; accessed 2026-10-15.
