What is cortisol?

What is cortisol?

Cortisol is a steroid hormone. It’s made by your adrenal glands and acts as a chemical messenger around your body. It plays a major role in your body’s stress response. It also helps your immune system and metabolism work properly.

Cortisol is often called the ‘stress hormone’, but it’s essential for keeping your body working properly. So it’s important that it stays balanced.

It’s normal for your cortisol levels to naturally rise and fall throughout the day. But if your cortisol levels are consistently too low or too high, this can impact your health.

What happens if cortisol is high?

Your cortisol is usually highest after you wake up in the morning, to help you have enough energy for the day ahead. Emotional or physical stress can also cause your cortisol levels to rise suddenly for a short time.

An uncommon condition called Cushing’s syndrome can cause high cortisol levels over a long time. Cushing’s syndrome is usually caused by taking high doses of steroid medication. Or, a small, non-cancerous growth in the pituitary gland (near the brain) or adrenal glands (near the kidneys) can cause too much cortisol to be released.

Not everyone with Cushing’s syndrome will have symptoms. But you might experience:

• fatigue
• high blood pressure
• weight gain
• reduced immune function
• emotional changes such as depression or anxiety

Raised cortisol from stress or daily changes is not the same as Cushing’s syndrome. Cushing’s typically leads to a pattern of ongoing symptoms.

What happens if cortisol is low?

Your body naturally lowers your cortisol level throughout the day, and it reaches its lowest level at night. This natural fall in cortisol helps your body rest and recover. You can also lower your cortisol levels with stress-reducing activities like yoga, mindfulness, and laughter.

If your body makes consistently low levels of cortisol, this can happen due to a condition called Addison’s disease. This is rare but needs medical treatment. It’s most commonly caused by an autoimmune response (when your body attacks its own healthy cells). Other causes include:

• genetic conditions that affect the adrenal glands
• infections like tuberculosis or HIV
• cancer and cancer treatments

If you have Addison’s disease you may not have any symptoms. But it can cause:

• fatigue
• weakness
• low blood pressure
• weight loss
• salt cravings

Low cortisol levels for a short time aren't the same as Addison’s disease. Addison’s is a long-term condition.

How do you know if you have high or low cortisol?

The only way to check your cortisol level is to have a cortisol test. However, doctors usually only recommend a test if they think you might have Addison’s disease or Cushing’s syndrome, which are not common. Most people with stress-related symptoms won’t need a cortisol test.

While everyday stress can affect cortisol levels in the short term, conditions like Addison’s disease and Cushing’s syndrome are uncommon and tend to cause long-term symptoms.

If you notice any sudden or unusual symptoms linked to adrenal crisis (a medical emergency where cortisol is extremely low), such as shock, nausea, abdominal pain or vomiting, seek medical help straightaway. You should also speak to your GP if you have prolonged symptoms, such as fatigue or unexplained weight changes, as these are potential signs of Addison’s disease or Cushing’s syndrome.

How to support healthy cortisol levels

If you have Addison’s disease or Cushing’s syndrome, you’ll need medical treatment to balance your cortisol levels.

If you don’t have one of these conditions, your body will usually keep your cortisol well balanced on its own. But to help support your wellbeing and keep your cortisol in a healthy range, it’s a good idea to manage stress.

A certain amount of stress can be positive because it can help you respond to situations. In the short term, it may even boost your focus and performance. For most people, this short-term stress is a normal and healthy response.

But too much stress for a long time (chronic stress) can mean you’re constantly in ‘fight or flight’ mode. This may negatively affect your health, general wellbeing, and increase your risk of mental health conditions. If chronic stress goes unmanaged it can also lead to ‘burnout’ – a state of intense mental, emotional, and physical exhaustion.

Cortisol is just one of many factors at play when it comes to stress and it naturally rises and falls throughout the day depending on what your body needs. So instead of focusing solely on your cortisol level, it’s best to focus on living as healthily as you can.

You can try reducing the effects of stress by:

• getting regular physical activity
• practicing good sleep habits
• eating a balanced diet and staying hydrated
• taking breaks
• trying yoga, deep breathing, or meditation
• doing a hobby or activity you enjoy
• spending time in nature
• connecting with friends or family

You can also reach out to a healthcare professional for support. With the right tools and self-care strategies, you can manage stress, feel more in control, and improve your overall wellbeing.