Cortisol and adrenal hormones: symptoms, testing and GP advice
Cortisol is a hormone produced by the adrenal glands that plays an essential role in the body’s response to stress, blood pressure regulation, metabolism and immune function. Cortisol levels naturally fluctuate throughout the day and rise during illness or physiological stress.
Concerns about cortisol imbalance are common, but true adrenal hormone disorders are uncommon. This page explains how GPs assess cortisol-related symptoms, when testing is appropriate, and why cortisol is not usually the cause of non-specific fatigue or stress-related symptoms.
These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help, please book an appointment with one of our GP’s.
What cortisol does in the body
Cortisol helps the body:
- Respond to physical and psychological stress
- Maintain blood pressure and circulation
- Regulate blood glucose levels
- Support immune and inflammatory responses
Cortisol levels follow a normal daily rhythm, highest in the morning and lowest at night.
Common symptoms people associate with cortisol imbalance
Many symptoms attributed to cortisol imbalance are non-specific and commonly caused by other conditions.
These may include:
- Fatigue
- Sleep disturbance
- Low mood or anxiety
- Weight changes
- Poor concentration
- Feeling overwhelmed or burnt out
In most cases, these symptoms are not caused by abnormal cortisol levels.
How GPs assess cortisol-related concerns
GP assessment focuses on:
- Symptom pattern and duration
- Medical history and medication use
- Sleep, stress and lifestyle factors
- Physical examination where appropriate
Testing is reserved for situations where there is a clinical suspicion of adrenal disease, rather than routine screening.
Cortisol testing explained
Blood cortisol tests
Blood cortisol is usually measured in the morning, when levels are expected to be highest.
Results are interpreted cautiously and in context.
Saliva and urine cortisol tests
These tests may be used in specialist settings but are not routinely recommended in primary care for non-specific symptoms.
Conditions affecting cortisol levels
Adrenal insufficiency
This is a rare but serious condition where the adrenal glands do not produce enough cortisol.
Symptoms may include:
- Persistent fatigue
- Weight loss
- Low blood pressure
- Dizziness
- Nausea or vomiting
Diagnosis requires specialist testing.
Cushing’s syndrome
This is a rare condition caused by prolonged high cortisol levels.
Features may include:
- Rapid weight gain, particularly around the abdomen
- Muscle weakness
- Easy bruising
- High blood pressure
This condition is uncommon and requires specialist assessment.
Cortisol and “adrenal fatigue”
The term “adrenal fatigue” is often used online to explain tiredness or stress-related symptoms. It is not a recognised medical diagnosis and is not supported by scientific evidence.
GPs focus instead on identifying and managing:
- Sleep problems
- Mental health conditions
- Chronic illness
- Lifestyle factors
- Medication effects
Addressing these factors is far more effective than cortisol testing in most cases.
When cortisol testing may be appropriate
Cortisol testing may be considered if:
- Symptoms suggest adrenal insufficiency
- There is unexplained low blood pressure or electrolyte imbalance
- There is concern about prolonged steroid use
- There are features suggestive of Cushing’s syndrome
Routine cortisol testing is not recommended for general fatigue or stress alone.
When to seek GP review
Consider GP review if:
- You have persistent unexplained fatigue
- You are on long-term steroid medication
- You have symptoms suggestive of adrenal disease
- You want help understanding whether hormone testing is appropriate
Related articles
Further Reading and Hub Links
Visit our Hormone Health hub or browse more health topics in the AccessGP Knowledge Base.
If you are concerned about symptoms possibly related to hormone balance, a GP can assess whether cortisol testing or further investigation is appropriate.
Last reviewed by Dr Zamiel Hussain, GMC registered GP
Updated: 31 December 2025