What is cortisol?

Cortisol is a steroid hormone made by your 2 adrenal glands, located on top of each kidney. When you feel stressed, your body releases more cortisol into your bloodstream. Having the right cortisol balance is important for your health. Producing too much or too little cortisol can cause health problems.

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

• your body respond to stress or danger
• increase your body's metabolism of glucose
• control your heart rate and blood pressure
• reduce inflammation
• growth and development of an unborn baby

Cortisol is also needed for your 'fight or flight' response, which is your healthy, natural response to perceived threats.

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 located at the base of your brain.

The release of cortisol can be influenced by:

• very warm or cold temperatures
• infections
• exercise
• traumatic or stressful events
• obesity
• some health conditions

Your pituitary gland reacts to these events and sends a signal to your adrenal glands to produce the right amount of cortisol.

Your body releases cortisol in a daily pattern, peaking in the morning and decreasing in the evening. If you work night shifts for an extended period, this pattern may change.

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 called Cushing's syndrome, your body produces too much cortisol. If you have a condition called Addison's disease, your body produces too little cortisol.

Symptoms of too much cortisol

Too much cortisol can lead to both physical and emotional symptoms. Physical symptoms may include:

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

Too much cortisol can also affect your mood. Emotional changes that can happen with Cushing's syndrome may include:

• depression
• anxiety
• mood swings
• difficulty concentrating
• lower sex drive (libido)

Symptoms of too little cortisol

Too little cortisol can cause physical and cognitive symptoms, such as:

• constant tiredness
• nausea and vomiting
• loss of appetite
• weight loss
• muscle weakness
• pain in the abdomen

Too little cortisol can also make it harder to concentrate. If you have Addison's disease you may also crave salty foods and get dark patches on your skin.

How are cortisol levels measured?

If you have symptoms of cortisol imbalance, your doctor may suggest a blood test to measure your cortisol levels. Cortisol levels change throughout the day. Your doctor may take several measurements at different times.

If they think you may have Cushing's or Addison's disease, they may do additional tests. These tests can include:

• different types of blood tests
• saliva tests
• urine tests

What are corticosteroid medicines?

Corticosteroids are medicines that are similar to cortisol. They work in the same way as the natural cortisol that your body makes. If your body doesn't make enough cortisol, such as in Addison's disease, your doctor may prescribe corticosteroids.

Corticosteroids are also called steroids, glucocorticoids or cortisones.

Corticosteroids are also used to treat a variety of health conditions, even if your body produces enough cortisol. Corticosteroids have anti-inflammatory effects and can be used to treat:

• inflammatory conditions — such as asthma, inflammatory bowel disease or arthritis
• skin conditions — such as psoriasis
• muscular degeneration — such as Duchenne muscular dystrophy
• autoimmune conditions

Anabolic steroids are synthetic versions of male sex hormones. They are different to corticosteroids. They can be used to treat hormonal problems in puberty and to help rebuild muscle in other conditions. Some people take anabolic steroids to build muscles, without a doctor's prescription. This is risky and not recommended.

What forms of corticosteroids are available?

Corticosteroids come in different forms. Corticosteroids can be given as:

• oral tablets
• liquids
• creams
• eye drops
• inhalations
• injections into veins or joints

What are the possible side effects or risks of corticosteroid therapy?

Corticosteroids are strong medicines. Side effects are quite common, especially if you need to take them for a long time. Short term use of steroids is unlikely to cause side effects.

Common side effects of long-term steroid treatment include:

• thinning or dry skin or acne
• osteoporosis
• increased appetite and weight gain, especially around your face
• a higher chance of getting infections and gastritis
• eye conditions, such as glaucoma and cataracts
• high blood pressure
• difficulty sleeping

Corticosteroids can raise your blood sugar, which may cause steroid-induced diabetes. If you have diabetes and are taking corticosteroids you should talk to your doctor or endocrinologist. Make sure to monitor your blood sugar levels more often.

You may also have rapid mood changes such as:

• feeling irritable
• anxiety
• depression
• suicidal thoughts

Always ask your doctor how long you need to to take corticosteroids and what to do if side effects happen. Your pharmacist can also advise you on this. Always follow your doctor's or pharmacist's instructions when taking corticosteroids.

When should I see my doctor?

If you notice any side effects or unusual symptoms when taking corticosteroids, talk to your doctor.

If you need long term steroid therapy, your doctor will perform regular blood tests. They will make sure that you are taking the right dose of steroids. This may change over time.

Resources and support

The Australian Pituitary Foundation provides information for adults and children with pituitary conditions such as Cushing's disease.

The Australian Addison's Disease Association provides information and resources for people with Addison's disease and their carers.

The Australian Addison's Disease Association also provides a FAQ page about taking corticosteroids.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Do you prefer to read in languages other than English?

Hormones Australia offers multilingual resources about hormone conditions such as Cushing's disease and Addison's disease.