How your thyroid is working can be assessed with a blood test that measures the levels of TSH (thyroid stimulating hormone) in your system. TSH is produced by the pituitary gland in your brain, and its job is to tell your thyroid what to do.

As part of the test the doctor may also request a check of other things at the same time – such as your T4 level (another thyroid hormone) or your cholesterol levels.

How do I get a TSH test?

A TSH test is part of a standard blood test taken at a laboratory such as Labtests.

Your doctor will tell you where your local laboratory is and give you a form to take with you. The test is free.

What should my TSH be?

Ideally your TSH should be between 0.3-4.0 mIU/L.

For pregnant women, your doctor may want to aim for a lower TSH of 0.1-2.5 or 3.0 mIU/L depending on the trimester.

For older people, a slightly higher range of 2.5-5.0 mIU/L may be the target.

Your doctor will tell you what your TSH is, and what they are hoping to achieve.

It also can be useful to record the TSH levels over time – and match them to how you are feeling.

What if I’m not at my TSH goal?

The dose of Eltroxin prescribed by your doctor is personalised to you, so some adjustment may be needed.

During that time your doctor may increase or decrease the dose and arrange for new TSH blood tests to see how you are going. It may take a couple of tries to get it right.