What is cortisol?

Cortisol is a steroid hormone that is produced by your 2 adrenal glands, which sit on top of each kidney. When you are stressed, increased cortisol is released into your bloodstream. Having the right cortisol balance is essential for your health, and producing too much or too little cortisol can cause health problems.

Cortisol has many important functions, acting on many different parts of your body. It can help:

• your body respond to stress or danger
• increase your body’s metabolism of glucose
• control your blood pressure
• reduce inflammation

Cortisol is also needed for the ‘fight or flight’ response, which is your healthy, natural response to perceived threats. The amount of cortisol produced is controlled by your body to ensure the balance is correct.

What triggers the adrenal glands to produce cortisol?

Cortisol production by your adrenal glands is regulated by your pituitary gland. This is a pea-sized gland at the base of your brain that is sometimes referred to as the ‘master gland’ because of its wide effects on your body.

When you wake up, exercise or face a stressful event, your pituitary gland reacts. It sends a signal to your adrenal glands to produce the right amount of cortisol.

What happens when you produce too much or little cortisol?

Usually, your body produces the right amount of cortisol to keep you healthy. If you have a condition such as Cushing’s syndrome, your body produces too much cortisol. If you have a condition such as Addison’s disease, your body produces too little cortisol.

Symptoms of too much cortisol include:

• weight gain, particularly around your abdomen and face
• thin and fragile skin that is slow to heal
• acne
• female facial hair and irregular menstrual periods

Symptoms of not enough cortisol include:

• continual tiredness
• nausea and vomiting
• weight loss
• muscle weakness
• pain in the abdomen

If you experience any of these symptoms, your doctor may suggest a blood test to measure your cortisol levels.

What are corticosteroid medicines?

Corticosteroids are synthetic versions of cortisol. If your body does not produce enough cortisol, for example, due to a condition such as Addison’s disease, your doctor may prescribe corticosteroids for you.

However, corticosteroids are also used to treat a wide variety of other diseases. Corticosteroids have anti-inflammatory effects and are their uses include treatment of inflammatory conditions (such as asthma and inflammatory bowel disease) and skin conditions (such as psoriasis). Your doctor may prescribe corticosteroid medicines to help treat these inflammatory conditions, even if your body produces enough cortisol.

Some people take anabolic steroids to build muscles, without a doctor’s prescription. This is risky. Anabolic steroids are different to corticosteroids.

What are the side effects of corticosteroid therapy?

Because corticosteroids are powerful medicines, side effects are quite common, particularly if you need to take steroids for a long time. Short courses of steroids are unlikely to cause side effects.

Side effects of long-term steroid treatment may include:

• thinning skin
• osteoporosis
• increased appetite and weight gain, especially around your face
• high blood sugar or diabetes
• rapid mood changes, feeling irritable and anxious, depression or suicidal thoughts
• an increased chance of infections
• eye conditions, such as glaucoma and cataracts
• high blood pressure

If your doctor prescribes you corticosteroids, be sure ask how long you need to take them, and what to do if you notice symptoms recurring or medication side effects. Your pharmacist can also advise you on this.