Urine Free Cortisol Test
500 Kshs | Home Collection Available
Synonyms
urinary free cortisol
Purpose
The Urinary Free Cortisol Test measures the amount of cortisol excreted in the urine over 24 hours. Cortisol is a hormone produced by the adrenal glands that plays a key role in regulating metabolism, blood pressure, immune response, and the body’s reaction to stress.
The test helps to:
- Diagnose and monitor Cushing’s syndrome, a condition caused by excess cortisol production
- Screen for adrenal gland disorders, including adrenal tumors or pituitary abnormalities
- Evaluate symptoms such as rapid weight gain, muscle weakness, high blood pressure, skin changes, irregular periods, or mood swings
- Assess suspected hypercortisolism in patients with uncontrolled diabetes, obesity, or early-onset hypertension
By collecting urine over 24 hours, the test provides a reliable reflection of cortisol production throughout the day, unlike single-time blood tests that can fluctuate with circadian rhythms.
To confirm diagnosis and provide a comprehensive assessment, the test can be done alongside Late-Night Salivary Cortisol Test, Low-Dose Dexamethasone Suppression Test (LDDST), Serum Cortisol Test, ACTH (Adrenocorticotropic Hormone) Test, and 24-Hour Urinary Creatinine.
Patient Preparation
Samples
100ml aliquot with a minimum volume of 10ml of urine 24-hour collected in a plastic urine container. All urine should be collected, including the final specimen at the end of the 24-hour collection period, mixed, and the lid secured. Label the container with the patient’s details (name, date of collection, time). Store the sample at room temperature.
Reference Range
18-80 years; 5-64 µg/24hr, >80 years 3-49µg/24hr
Results Turnaround
4-6days after receipt of samples.
Diseases / Diagnostic indicators
The Urinary Free Cortisol Test is primarily used to evaluate for Cushing’s syndrome, a condition caused by excess cortisol production over time. This condition may result from:
- Cushing’s disease – overproduction of ACTH by a pituitary tumor
- Adrenal tumors – producing cortisol directly, independent of ACTH
- Ectopic ACTH-producing tumors – such as small-cell lung cancer
- Prolonged corticosteroid use – leading to symptoms of Cushing’s syndrome (iatrogenic Cushing’s)
Common symptoms prompting testing include:
- Rapid weight gain (especially in the face, abdomen, and upper back)
- Muscle weakness and thinning of the skin
- Easy bruising and purple stretch marks
- High blood pressure and high blood sugar
- Mood swings, irritability, or depression
The test results may indicate:
Elevated Cortisol Levels:
This suggests hypercortisolism, which may be due to Cushing’s syndrome, stress, certain medications, or a cortisol-producing tumor. Further tests (like dexamethasone suppression or imaging) are usually required to confirm the cause.
Normal Cortisol Levels:
Suggest that cortisol production is within the normal range. This generally rules out Cushing’s syndrome, though repeat testing may be necessary if symptoms persist or are intermittent.
Low Cortisol Levels:
Though not the primary use of this test, abnormally low results may indicate adrenal insufficiency or Addison’s disease, especially if accompanied by fatigue, weight loss, and low blood pressure. Blood tests are typically used for confirmation.
This test is a reliable tool for assessing cortisol levels over a full day, helping clinicians detect underlying endocrine disorders that may otherwise be missed with single-time-point testing. For more on the Urine Free Cortisol Test, read this study.