Cortisol
Private Cortisol blood test in London for £99, measuring one adrenal hormone marker with results expected in around 1 business day.
Turnaround time
1 day
Biomarkers count
1
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Overview of the Cortisol
The Cortisol blood test measures cortisol, the principal glucocorticoid steroid hormone produced by the adrenal cortex.
The test contains 1 biomarker: Cortisol.
Cortisol plays important roles in glucose metabolism, blood-pressure regulation, immune responses and the body's adaptation to physical stress.
Cortisol follows a strong circadian rhythm.
Levels are normally highest in the early morning and fall progressively through the day, reaching their lowest concentrations at night.
For this reason, the time of blood collection is essential for interpretation.
A morning Cortisol measurement can provide useful initial information when adrenal insufficiency is being considered.
However, one Cortisol result does not always confirm or exclude adrenal disease.
Intermediate results may require dynamic testing such as an ACTH stimulation test.
Likewise, a high random Cortisol measurement does not diagnose Cushing syndrome.
Investigation of suspected cortisol excess generally uses validated tests such as dexamethasone suppression, late-night salivary cortisol or urinary free cortisol.
Cortisol is also affected by acute illness, psychological stress, sleep, pregnancy and medication.
What Does the Cortisol Test Check?
This test measures 1 biomarker.
Cortisol
Measures circulating cortisol, the body's principal glucocorticoid hormone. Interpretation depends strongly on the time of day and clinical reason for testing.
Who May Benefit From the Cortisol Test?
ortisol testing may be useful where adrenal hormone production requires assessment.
People being investigated for adrenal insufficiency - A correctly timed morning Cortisol provides useful initial information.
People with known adrenal disease - Cortisol may form part of specialist monitoring.
People with pituitary disease - Pituitary ACTH controls adrenal Cortisol production.
People who have used systemic corticosteroids - Prolonged steroid treatment can suppress natural Cortisol production.
People with unexplained low blood pressure and other compatible findings - Cortisol may form part of a broader endocrine investigation.
People undergoing specialist assessment of possible cortisol excess - Serum Cortisol may provide supplementary information.
People with a previous abnormal Cortisol result - Repeat testing at a clearly documented time may clarify the pattern.
People specifically advised to obtain a morning Cortisol - Correct timing is particularly important.
How to Prepare
Do not stop prescribed corticosteroids abruptly before testing.
Sudden withdrawal after prolonged steroid treatment can be dangerous because natural adrenal Cortisol production may remain suppressed.
Symptoms and Reasons to Consider the Cortisol Test
Symptoms associated with cortisol abnormalities vary considerably depending on whether cortisol production is too low or excessively high.
Persistent unexplained fatigue - Low cortisol can contribute to profound tiredness, although fatigue has many other causes.
Muscle weakness - Altered cortisol production can contribute to weakness in some endocrine disorders.
Unexplained weight loss - Adrenal insufficiency can be associated with weight loss and reduced appetite.
Low blood pressure or recurrent light-headedness - Cortisol deficiency can contribute to hypotension.
Unexplained nausea or abdominal symptoms with other adrenal features - Gastrointestinal symptoms can occur in adrenal insufficiency.
Unexplained weight gain around the trunk or face - Cortisol excess can cause characteristic changes in fat distribution.
Easy bruising or thinning skin - Chronic cortisol excess can affect skin and connective tissue.
Purple or wide stretch marks - These can occur in cortisol excess but are not diagnostic by themselves.
High blood pressure with other features of cortisol excess - Cushing syndrome can contribute to hypertension.
Symptoms after reducing long-term steroid medication - Previous corticosteroid treatment can suppress natural adrenal function.
These symptoms are not specific to Cortisol disorders and can occur with many more common conditions.
Severe weakness, vomiting, dehydration, very low blood pressure, confusion or collapse in someone at risk of adrenal insufficiency can indicate an adrenal crisis and requires emergency medical treatment.
How to Book Your Cortisol Test
Booking your Cortisol blood test with London Blood Tests is straightforward.
Choose the Cortisol
Select the individual Cortisol blood test and confirm whether a particular collection time has been requested.
Select your sample collection option
Choose an in-clinic blood draw or professional home or hotel phlebotomy at the clinically appropriate time.
Attend your appointment
A trained healthcare professional collects the blood sample and the collection time should be documented.
Laboratory analysis
Your serum is analysed for Cortisol concentration.
Receive your results securely
Your authorised result is delivered securely.
When Will I Receive My Results?
The current expected turnaround is approximately 1 business day after laboratory receipt.
Results are sent securely by email once specialist laboratory analysis and authorisation are complete. Turnaround generally begins when the laboratory receives your blood sample rather than necessarily from the time it is collected.
Specialist serology can occasionally require repeat analysis, confirmatory review or additional laboratory processing, which may extend the expected turnaround.
Understanding Your Results
Cortisol cannot be interpreted correctly without knowing the time of sample collection.
A low morning Cortisol may raise concern about adrenal insufficiency.
Very low concentrations can be strongly suggestive in the correct context, while intermediate values often require further investigation.
Higher Cortisol can occur because of physiological stress, acute illness and several other conditions.
A high random result does not diagnose Cushing syndrome.
Where pathological cortisol excess is suspected, specialist testing designed to assess suppression or circadian rhythm is usually required.
Pregnancy and oestrogen therapy can increase cortisol-binding globulin and therefore raise total measured Cortisol.
Why Book With London Blood Tests?
Private Cortisol testing in London - Access targeted adrenal hormone measurement privately.
Clinically timed testing available - Morning sampling can be arranged where appropriate.
Relevant to adrenal assessment - Cortisol is central to investigation of adrenal function.
Useful alongside ACTH - Combined hormone results can help guide further endocrine testing.
Fast results - Results are expected approximately 1 business day after laboratory receipt.
Trusted UK laboratories - Samples undergo professional endocrine analysis.
Clinic and home collection options - Professional phlebotomy can be arranged at an appropriate time.
Clear pricing - The Cortisol test costs £99.
Private Cortisol Blood Test in London
London Blood Tests provides private Cortisol blood testing in London for people requiring targeted assessment of adrenal glucocorticoid production.
The test costs £99 and measures one biomarker: Cortisol.
Results are expected approximately 1 business day after laboratory receipt.
The collection time is particularly important, and one Cortisol value should not be used alone to diagnose adrenal insufficiency or Cushing syndrome.