
ABOUT THIS TEST
What are the thyroid tests and why are they important?
The thyroid tests are used to evaluate the function of the thyroid gland; to help diagnose thyroid gland disorders. The thyroid hormones regulate the body’s metabolism and how it grows, functions and uses energy.
The thyroid gland is located at the front of the neck. It secretes two hormones known as thyroxine (T4) and tri-iodothyronine (T3). The release of T4 and T3 into the blood is controlled by a third hormone called thyroid stimulating hormone (TSH), this hormone is responsible for keeping FT4 and FT3 at the right levels. Collectively, these three hormones are referred to as ‘thyroid function tests’ (TFTs).
There are two main conditions the effect the thyroid
- Hypothyroidism (know as underactive thyroid) is when the thyroid glands fails to produce sufficient hormones for health. This can be treated by thyroid hormone replacement.
- Hyperthyroidism (known as overactive thyroid) is when the thyroid gland produces too much thyroid hormone. This can be treated by hospital specialist depending on the cause.
Please note: these tests are available for people aged over 18 only. In a small number of cases, it may not always be possible to provide a result, please see our terms and conditions for details.
WHO IS THIS TEST FOR
People who may benefit from having a thyroid function test include:
Individuals who are concerned that they may have a thyroid problem and those who wish to monitor a previously diagnosed condition.
Early signs and symptoms of thyroid dysfunction may often be very non-specific. The common symptoms hypothyroidism may include:
- Unexplained weight gain
- Dry skin
- Feeling cold
- Puffy skin
- Hair loss
- Tiredness
Some signs and symptoms of hyperthyroidism may include:
- Fast heart rate
- Anxiety
- Unexplained weight loss
- Feeling hot
- Hand tremors
- Bulging, dry, puffy or irritated eyes
- Difficulty sleeping (insomnia)
What will the result show?
Our thyroid test will report your levels for all three hormones (TSH, FT4 and FT3). You will receive a personalised interpretation of what the results mean and what you should do about them. This may be as simple as; all is well, to a recommendation to see your GP if we detect an abnormality.
In hypothyroidism, the thyroid gland does not produce sufficient thyroxine, so the T4 and T3 levels are low.
This causes an increase in TSH to try and stimulate the thyroid to produce more thyroxine.
In hyperthyroidism the thyroid gland produces too much thyroxine, so the T4 levels are high. This causes a decrease in TSH to try and stop the thyroid producing more thyroxine.



"I use MMH to keep an eye on my thyroid levels and as it's an NHS lab, my GP and endocrinologist can use the results to monitor me. I was grateful for having the option of home testing last year, when I was unable to get to my surgery due to ill health. Very quick service and I like the graphs showing my health journey."
Susan Andrews