Description
Cortisol Blood Test — What It Is and Why It’s Important
A cortisol blood test measures the amount of cortisol — one of the body’s key hormones — circulating in your blood. Cortisol is produced by your adrenal glands, which are small, triangular glands that sit on top of your kidneys. While cortisol is widely known as the “stress hormone” because of its role in helping your body respond to stress, it also plays several other critical roles. It helps regulate your metabolism, control blood sugar levels, maintain blood pressure, support your immune system, and manage inflammation throughout the body. Having the right balance of cortisol is essential for your overall health and wellbeing.
Why You Might Need a Cortisol Test
A cortisol blood test is often recommended if you suspect your cortisol levels might be too high or too low. Elevated cortisol levels can lead to a condition called Cushing’s syndrome, which is often associated with symptoms like significant weight gain, particularly around the face and abdomen, the development of a rounded, puffy face (sometimes called a “moon face”), high blood pressure, muscle weakness, mood disturbances such as anxiety, irritability, or depression, and skin changes including thinning and easy bruising.
On the other hand, if cortisol levels are too low, it may point to Addison’s disease. Symptoms of low cortisol include severe and ongoing fatigue, unexplained weight loss, low blood pressure, darkening of the skin especially in scars or skin folds, intense cravings for salty foods, and muscle or joint pain.
Cortisol testing is also an important tool for individuals experiencing long-term stress, as chronic stress can affect cortisol production. It may be recommended for people who have known adrenal gland disorders, those who are taking steroid medications (which can interfere with natural cortisol production), or for patients dealing with abnormal blood sugar levels or unexplained metabolic problems. In all of these cases, checking cortisol levels can provide valuable insight into what might be happening inside the body.
How the Test Works
Cortisol levels are not constant throughout the day; they naturally follow a daily rhythm, peaking in the early morning and reaching their lowest levels at night. Because of this daily cycle, the timing of your blood test is very important. Most cortisol blood tests are scheduled early in the morning, typically between 7:00 and 9:00 AM, when cortisol levels are expected to be at their highest. In some cases, your healthcare provider might request a second sample later in the afternoon to observe how your cortisol levels decline throughout the day, which can provide further information about how your adrenal glands are functioning.
Understanding your cortisol levels is a key part of diagnosing hormone imbalances, adrenal gland issues, and understanding unexplained symptoms like fatigue, weight changes, or mood disturbances. A cortisol blood test offers an important window into how well your body is managing stress and maintaining critical metabolic and immune functions.
How often should I have a Cortisol blood test?
We recommend checking your cortisol levels every 3-6 months, if you are choosing to monitor levels over time.
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
- Fatigue
- Weight changes
- Mood disturbances
- Muscle weakness
- Changes in blood pressure
This blood test is to check on:
- Cortisol
For best results, take the test first thing in the morning (due to cortisol levels being highest then).
Collection method: Venous blood
Results available: 1-2 days after the sample has reached the laboratory.
Cortisol
A cortisol blood test measures the level of cortisol which is a hormone made by your adrenal glands. A cortisol blood test helps assess your body’s stress response and adrenal health, and can uncover hormone imbalances that affect your overall well being.
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.
