TSH Blood Test Explained – What It Shows and Why It Matters
Book a private TSH blood test in London with same-day results at Marylebone Diagnostic Centre, 73 Baker Street. Fast, discreet, and accurate thyroid health testing.
Your thyroid plays a central role in energy, weight control, mood, and overall wellbeing. When it is not working properly, you may feel exhausted, gain or lose weight unexpectedly, or struggle with concentration. These symptoms are common and often overlooked, but they could point to thyroid imbalance.
The most reliable way to check thyroid function is with a TSH blood test. At Marylebone Diagnostic Centre (MDC), 73 Baker Street, London, we offer same-day thyroid testing so you can get quick, clear answers about your health.
What is a TSH blood test?
TSH stands for thyroid-stimulating hormone. It is made by the pituitary gland and tells your thyroid when to release hormones (T3 and T4).
- High TSH levels usually mean the thyroid is underactive (hypothyroidism).
- Low TSH levels may indicate the thyroid is overactive (hyperthyroidism).
Doctors often use the TSH test as a first-line investigation because it gives an early signal of thyroid problems.
Why is the TSH test important?
Thyroid imbalance can affect almost every system in the body. Common symptoms include:
- Fatigue and low energy
- Weight gain or loss without changes in diet
- Feeling cold or overheated
- Depression, anxiety, or mood swings
- Thinning hair and brittle nails
- Memory and concentration problems
- Menstrual irregularities in women
Because these symptoms are often vague, many patients live with thyroid issues undiagnosed. The TSH test provides a straightforward way to check if the thyroid is responsible.
What does the TSH test show?
A typical TSH blood test result falls between 0.4 and 4.0 mIU/L (but ranges can vary).
- Low TSH – possible hyperthyroidism, where the thyroid is overactive.
- High TSH – possible hypothyroidism, where the thyroid is underactive.
- Borderline results – may need repeat testing or further hormone checks.
At MDC, we often combine TSH with other thyroid markers for a full assessment.
What other thyroid tests are available?
A full Thyroid Function Profile at MDC may include:
- Free T4 and Free T3: confirm how much thyroid hormone is circulating.
- Thyroid antibodies (TPOAb, TgAb, TRAb): check for autoimmune thyroid disease such as Hashimoto’s or Graves’ disease.
- Additional blood tests: to rule out other causes of fatigue or weight change, such as iron or vitamin deficiencies.
Book your Thyroid Profile at MDC
How is the test done?
The process is quick and simple:
- Book your appointment online or by phone.
- A small blood sample is taken by a trained phlebotomist.
- Results are available the next day in most cases.
- Our doctors explain the results and recommend next steps.
Who should book a TSH test?
You may benefit from thyroid testing if you:
- Experience unexplained fatigue, weight change, or mood shifts
- Have a family history of thyroid problems
- Are pregnant or planning pregnancy (thyroid function affects fertility and development)
- Take medication that can influence the thyroid
- Are over 40 and want a baseline check
FAQs about TSH testing
Why choose MDC for thyroid testing?
- Central London location – 73 Baker Street
- Same-day results available
- Comprehensive thyroid profiles (TSH, T3, T4, antibodies)
- No GP referral needed
- Discreet, professional care with follow-up advice
The TSH blood test is a simple but powerful way to understand thyroid health. Whether you are experiencing symptoms or simply want reassurance, it provides clarity and peace of mind.
At Marylebone Diagnostic Centre, 73 Baker Street, London, we provide same-day TSH and thyroid profiles to give you answers quickly.
Book your thyroid blood test today at Marylebone Diagnostic Centre.
73 Baker Street, London
+44 7495 970109
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