Private Thyroid Test (TSH and Free T4): £55, results in 24 hours
TSH and free T4, the standard thyroid function test, £55
The thyroid function test (TFT) every GP starts with: TSH, the pituitary signal that rises when the thyroid is underactive and falls when it is overactive, and free T4, the thyroid hormone itself. Reviewed by a doctor who explains the pattern, with results emailed within 24 hours. No fasting and no GP referral needed. Have your blood taken at our Kings Heath clinic in Birmingham with no blood-draw fee, at one of 100+ partner clinics across the UK, or at home.
Includes: both markers, the lab fee, a doctor’s review of your results and a written report by email, usually within 24 hours, explaining what the TSH and free T4 pattern means. Nothing to pay on the day at the Birmingham clinic.
Book a thyroid test online- No referral needed
- No fasting
- Results in 24 hours
- Doctor-reviewed
- CQC-registered clinic
What a thyroid test checks
The thyroid sets the pace of the body’s metabolism, and the pituitary gland controls it with TSH. Because the two move in opposite directions, measuring both tells you not just whether the thyroid is under- or overactive but also whether the problem is in the thyroid itself or in the signal reaching it. TSH alone is the screening test; TSH with free T4 is the test that gives an answer.
- TSH thyroid-stimulating hormone (thyrotropin), the signal the pituitary gland sends to the thyroid. It is the most sensitive thyroid marker and moves in the opposite direction to the thyroid itself: a HIGH TSH means the thyroid is underactive and the pituitary is pushing it harder; a LOW TSH means the thyroid is overactive and the pituitary has eased off.
- Free T4 free thyroxine, the main hormone the thyroid makes, measured as the unbound fraction that is actually available to the body. Read with TSH: low free T4 with a high TSH is an underactive thyroid (hypothyroidism); high free T4 with a low TSH is an overactive one (hyperthyroidism). It is also the marker that shows whether a levothyroxine dose is right.
When to have one
Thyroid disease is common, especially in women, and its symptoms are easy to put down to stress, age or lifestyle. A thyroid test is worth having if any of these apply:
- Tiredness, feeling the cold, weight gain, constipation, dry skin, thinning hair, low mood or heavy periods: the signs of an underactive thyroid
- Weight loss, a racing heart or palpitations, feeling hot and sweaty, anxiety, tremor, loose bowels or light periods: the signs of an overactive thyroid
- A family history of thyroid disease, or another autoimmune condition such as type 1 diabetes, coeliac disease or vitiligo
- You are planning a pregnancy, are pregnant, or had a baby in the past year (thyroid problems often start after childbirth)
- You take levothyroxine and want to check the dose, or you take lithium, amiodarone or an immunotherapy that can affect the thyroid
- A swelling in the neck, or a previous result that was borderline and needs rechecking
What happens
- Book online and choose where to have your blood taken: the Kings Heath clinic, a partner clinic near you or a home visit. Pay once; there is nothing to pay on the day.
- Give one small blood sample. It takes a few minutes. No fasting is needed; a morning sample is ideal if you take levothyroxine, taken after the blood test rather than before.
- The lab measures TSH and free T4 at a UKAS-accredited laboratory, usually the same day.
- A doctor reviews your results and emails you a written report, usually within 24 hours, explaining the pattern: normal, underactive, overactive, or one of the in-between (subclinical) patterns that need a repeat test.
- If something needs following up, the report says what: usually a repeat test in six to eight weeks, thyroid antibodies to look for the autoimmune cause, or a GP appointment to start or adjust treatment. We write to your NHS GP with your consent.
How to prepare
- No fasting. Eat and drink normally.
- If you take levothyroxine, have the test in the morning before that day’s dose, and tell us the dose: taking it just before the test raises free T4 for a few hours.
- Stop biotin (vitamin B7, in many hair and nail supplements) for 48 hours before the test. It interferes with the laboratory method and can make the thyroid look overactive.
- Do not test within six weeks of a significant illness, which disturbs thyroid results temporarily, unless the thyroid is the question.
Where to have your blood taken
The test, the laboratory and the doctor’s report are the same wherever you live. Only the blood-draw fee differs, and it is charged once per visit however many tests you add.
Want more from the same sample? Add a full blood count and ferritin (the tiredness trio), vitamin D or HbA1c and cholesterol and the blood is taken once, with the multi-test discount applied at checkout.
Normal ranges and what a high result means
| Marker | Typical adult range |
|---|---|
| TSH | 0.3 to 4.2 mU/L |
| Free T4 | 12 to 22 pmol/L |
Typical adult ranges. Every laboratory sets its own, which can differ slightly from these, and your report shows the range the lab used. In pregnancy the TSH range is lower, and on levothyroxine most people feel best with a TSH in the lower half of the range. TSH is the more sensitive marker and moves first: a result just outside the range is read with the free T4, not on its own.
Thyroid results are read as a pair, and the pattern is what matters. High TSH with low free T4 is an underactive thyroid (hypothyroidism), usually autoimmune and treated with levothyroxine. Low TSH with high free T4 is an overactive thyroid (hyperthyroidism), most often Graves’ disease. High TSH with a normal free T4 is “subclinical” hypothyroidism, which is common, often settles, and is repeated after a few weeks before anything is decided; low TSH with a normal free T4 is the overactive equivalent. These are the tests we add when a result needs explaining, all bookable at the same clinic:
Questions people ask
What does a thyroid blood test show?
The standard thyroid function test measures TSH, the pituitary hormone that controls the thyroid, and free T4, the hormone the thyroid makes. Together they show whether the thyroid is working normally, underactive (hypothyroidism) or overactive (hyperthyroidism), and whether the problem is in the thyroid itself or in the signal to it. For someone on levothyroxine, they show whether the dose is right. The report explains the pattern in plain English.
What is a normal TSH level?
Roughly 0.3 to 4.2 mU/L in most UK laboratories, with free T4 of 12 to 22 pmol/L; your report shows the range the lab used. TSH moves in the opposite direction to the thyroid: high means underactive, low means overactive. The range is lower in pregnancy, and people on levothyroxine often feel best with a TSH in the lower half of the range. A TSH just outside the range with a normal free T4 is repeated before any decision is made.
What does a high TSH with a normal T4 mean?
This is subclinical hypothyroidism: the thyroid is still producing enough hormone, but the pituitary is having to push it harder. It is common, especially in women and with age, and up to half of mild cases return to normal on their own, so the test is repeated after six to eight weeks, usually with thyroid antibodies. Treatment with levothyroxine is considered if the TSH is above 10, if it stays raised and you have symptoms, if antibodies are positive, or if you are pregnant or planning to be.
What does a high TSH with a low T4 mean?
An underactive thyroid (overt hypothyroidism). The thyroid is not making enough hormone despite the pituitary pushing it, and the symptoms, tiredness, weight gain, feeling the cold, low mood and dry skin, usually fit. In the UK the commonest cause is autoimmune (Hashimoto’s) thyroiditis, confirmed with TPO antibodies. It is treated with levothyroxine, a daily tablet, with the dose adjusted by repeat tests until the TSH is back in range, after which a yearly check is enough.
What does a low TSH with a high T4 mean?
An overactive thyroid (hyperthyroidism): the thyroid is making too much hormone and the pituitary has switched off its signal. The symptoms are weight loss, a racing heart, sweating, anxiety, tremor and loose bowels. The commonest cause is Graves’ disease; others are a nodule or an inflamed thyroid after a virus or pregnancy. It needs prompt treatment, so a result like this is followed by free T3 and antibodies and a GP or endocrinology appointment.
What does a low TSH with a normal T4 mean?
Subclinical hyperthyroidism: the thyroid is slightly overactive but the hormone level is still in range. It can be an early overactive thyroid, a nodule, or, commonly, too high a dose of levothyroxine. Free T3 is added, because it rises before T4 in early Graves’ disease, and the test is repeated in a few weeks. A persistently low TSH is treated in older people and anyone with heart rhythm problems or osteoporosis, as it raises the risk of both.
How much does a private thyroid test cost?
£55 at OneMedicine for TSH and free T4, which includes the laboratory fee, a doctor’s review and a written report by email. There is no blood-draw fee at our Birmingham clinic. At a partner clinic elsewhere in the UK the blood-draw fee is £29, and a home visit in England is £60, charged once per visit however many tests you have. The comprehensive panel with antibodies is £145.
Do I need to fast before a thyroid test?
No. Eat and drink normally. Two things do matter: if you take levothyroxine, have the test before that day’s dose, and stop biotin (vitamin B7) supplements for 48 hours, because biotin interferes with the laboratory method and can produce a falsely overactive result.
Can I test my thyroid at home?
Finger-prick thyroid kits exist, but a small or clotted sample often fails and the result still needs a doctor to read the pattern. The accurate test is a venous blood sample. If getting to a clinic is difficult, book a home visit and a phlebotomist takes the sample at your home anywhere in England; the laboratory and the doctor’s report are the same.
Should I have thyroid antibodies tested?
Not as a first test. TPO antibodies and thyroglobulin antibodies show whether a thyroid problem is autoimmune, which is the commonest cause of both an underactive thyroid (Hashimoto’s) and an overactive one (Graves’). They are the next step when TSH or free T4 is abnormal, when a subclinical result needs a decision, when you are planning a pregnancy with a borderline TSH, or when symptoms persist despite a normal TSH. The comprehensive thyroid panel includes both antibodies with free and total T3 and T4.
Read more
- Understanding Your Thyroid Blood Test (TSH and T4)
- Thyroid Antibodies: Hashimoto’s and Graves’ Explained
- Thyroid and Weight: The Real Connection
- Selenium and Thyroid Health
OneMedicine, 1 High Street, Kings Heath, Birmingham B14 7AR. Opposite Kings Heath railway station, on-site parking. CQC-registered.
