Description
Thyroid Blood Test – Understand What Your Body Is Telling You
Thyroid problems are more common than many people realise, particularly in women. This small gland in your neck has a huge impact on your overall wellbeing—regulating your metabolism, energy, temperature, heart rate, and even your mood. When something goes wrong with your thyroid, the symptoms can be wide-ranging and often mistaken for other health conditions like menopause, vitamin deficiencies, or anaemia.
Because the signs of thyroid dysfunction are so easily overlooked or misattributed, a thyroid blood test is one of the most effective ways to find out what’s really going on.
Why Take a Thyroid Blood Test?
The thyroid gland produces hormones—mainly thyroxine (T4) and triiodothyronine (T3)—that control how your body uses energy. These hormones help regulate critical functions such as your metabolic rate, body temperature, and muscle strength. When your thyroid produces too much or too little of these hormones, it can throw your entire system out of balance.
A thyroid blood test checks your hormone levels and can identify whether your thyroid is underactive, overactive, or functioning normally. This insight can be crucial if you’re dealing with unexplained symptoms and need clarity before starting treatment or making lifestyle changes.
There are two main types of thyroid disorders: hypothyroidism and hyperthyroidism. Each comes with its own distinct set of symptoms and requires different approaches to treatment.
Hypothyroidism – Underactive Thyroid
Hypothyroidism occurs when the thyroid doesn’t produce enough hormones. It’s the most common thyroid disorder and often develops slowly over time. Many people live with the symptoms for years, thinking they’re just “getting older” or feeling run-down.
Symptoms of hypothyroidism can include:
- Constant fatigue, no matter how much rest you get
- Unexplained weight gain or difficulty losing weight
- Sensitivity to cold – always feeling chilly
- Dry or rough skin
- Thinning or brittle hair, sometimes leading to hair loss
- Constipation or sluggish digestion
- Low mood, irritability, or even clinical depression
- Brain fog – struggling to focus or remember things
- A hoarse or croaky voice
- Slower heart rate and reduced stamina
If left untreated, hypothyroidism can worsen over time and may lead to more serious issues such as infertility, heart problems, or goitre (swelling of the thyroid gland).
Hyperthyroidism – Overactive Thyroid
Hyperthyroidism happens when the thyroid becomes overactive and produces too much hormone. This speeds up your metabolism and can make you feel overstimulated or anxious. It’s commonly caused by an autoimmune condition called Graves’ disease, which can also cause eye symptoms like bulging or irritation.
Symptoms of hyperthyroidism can include:
- Nervousness, anxiety, or a sense of restlessness
- A racing or irregular heartbeat (palpitations)
- Excessive sweating, even in cool environments
- Unintended weight loss
- Difficulty falling or staying asleep
- Weakness in the muscles, especially in the upper arms or thighs
- Shaky hands or trembling fingers
- Thinning hair, fragile skin, or brittle nails
- Increased sensitivity to heat
- Bulging eyes or a staring appearance (in Graves’ disease)
Hyperthyroidism can also disrupt your menstrual cycle, increase the risk of osteoporosis, and—if untreated—can lead to a life-threatening condition called thyroid storm.
How to test for hyperthyroidism
Testing for hyperthyroidism can be done with a nurse-taken venous blood test that will measure the thyroid hormones (thyroxine (FT4) and the thyroid stimulating hormone (TSH) in your blood. Results that show a high thyroxine and low TSH levels indicate an overactive thyroid gland.
Treatment for hyperthyroidism, or an overactive thyroid, should be discussed with your GP or healthcare professional and can include medication, surgery or a substantial dose of radioactive iodine.
If the thyroid gland doesn’t produce enough of the thyroid hormones, hypothyroidism – or an underactive thyroid – will occur and has different symptoms.
How often do I need to check my thyroid levels
We recommend checking your thyroid levels when you experience any health changes or symptoms listed.
Our Nurses visit your Home or Work to take your blood.
Pick a time and date to suit you.
Your results are available online within days of your blood being taken.
Other Questions
- Dry skin
- Fatigue
- Increased sensitivity to the cold
- Constipation
- Slow heart rate
- Weight gain
- Memory issues
- Depression
- Weakness
- Anxiety
- Nervousness
This blood test is to check on:
- Thyroid function
For best results (if medically suitable) it is advisable to fast (water is allowed) 12 hours prior to the test.
Collection method: Venous blood
Results available: 1-2 daysafter the sample has reached the laboratory.
Free Thyroxine (Free T4)
This test will measure the amount of free thyroxine in your blood, it will measure how well your thyroid gland is working. T4 is one of the major thyroid hormones in your blood. If the results are too high or too low it can indicate thyroid disease.
Free T3 (FT3)
This test measures the level of triiodothyronine (T3) in your blood. T3 along with T4 are the two major thyroid hormones in your blood. T3 blood test may be used to diagnose hyperthyroidism. If the results are too high or too low it can indicate thyroid disease.
Thyroid Stimulating Hormone (TSH)
This test will measure how much TSH is in your blood.
TSH is made in your pituitary, (a gland in your brain) when your thyroid levels are low the pituitary gland makes more TSH and when the thyroid levels are high your pituitary makes less TSH This result indicates how well the thyroid is working.
How it Works
1. Order a Test
Order your test, and then Answer the Questions about why you’re taking that test.
Our nurse will contact you for dates, so they can take your blood sample at your home.
Our nurse will then send your sample to our laboratory.
2. Our laboratory team run the tests
Our skilled laboratory staff conduct your blood tests in a clean and secure environment, ensuring accuracy and reliability.
Each test follows strict protocols to maintain the highest quality standards.
3. Receive Your Results within 7 days
We will email you to inform you that your blood test results are ready.
The email will have a PDF report attached, sent directly to your inbox.
4. Monitor your levels over time
With regular ongoing tests and reports, you can track your results. The reports can be shared with your GP.
Check if you’re improving healthily or where changes could be made.
