5 min read

Cortisol: Stop stressing about this hormone!

a white woman with glasses resting on her head sits in front of a gray laptop massaging her temples. From her expression, she seems to have high cortisol levels and be experiencing stress.
Content Editor & Certified Trainer
Lisa studied journalism and is a certified fitness and health trainer, as well as a meditation coach! She spent many years working for different lifestyle and fitness magazines, and she writes articles for us on the topics of working out, fitness, lifestyle and mind.

Cortisol is a major stress hormone. In the short term, it boosts performance, but a permanently elevated cortisol level can be harmful. Here we will lay out more about the effects of cortisol and the three best anti-stress techniques.

What is cortisol?

Cortisol (or: hydrocortisone) is produced in the adrenal glands and is the most well-known stress hormone after adrenaline. It activates catabolic metabolic processes, i.e. breakdown processes in the body that provide energy. 

Cortisol does not have a very good reputation, but  wrongly so: this steroid hormone is in fact vital. In the short term, it serves as an important defense for the body against stress and inflammation. However, if the hormone is produced constantly, with chronic stress for example, cortisol can have negative effects, including on your ability to concentrate and sleep. 

Reference values of cortisol

Cortisol is essential. But too much can quickly damage your health. But at what point do your cortisol levels really become a concern? 

Our levels of cortisol generally fluctuate throughout the day. In the morning we are more active, and the body releases more cortisol. In the evening, the body prepares for rest and reduces production. 

Overview of cortisol values:

(in micrograms per liter of saliva in men and women at least 18) 

Time Reference Range 
7 – 9 AM 0.60 – 8.40µg/l
9 – 11 AM 0.40 – 5.30µg/l
12 – 14 PM < 3.10µg/l
17 – 19 PM < 1.40µg/l
22 – 24 PM < 0.80µg/l

Important: The reference values may differ from laboratory to laboratory. In addition, there may be strong daily and seasonal fluctuations with no pathological findings. Consulting a doctor can clarify any concerns.

Effects of cortisol

In acute stress situations, for example if you are taking an exam or exercising strenuously, the adrenal gland releases cortisol. Together with the neurotransmitters noradrenaline and adrenaline, cortisol signals the brain to provide glucose as an energy source. Your blood pressure rises, your heart pumps faster, fat metabolism is activated, and inflammatory reactions in the body are inhibited. As a result, you alert, have increased concentration, and feel more powerful. 

If, however, this stress is not acute but rather persistent – for example, if you have been under physical or emotional stress for weeks – the increased cortisol release can pose a problem. If it’s released continuously, it can cause both physical and psychological complaints.

What happens if cortisol levels are too high?

Chronically elevated cortisol levels are often associated with heart disease and high blood pressure. An excess of the neurotransmitter is also problematic for the brain: studies have shown that too much cortisol damages the nerve cells in the hippocampus – the area responsible for your learning ability and memory. Your memory can suffer and you may have difficulty concentrating. 

Reduced quality of sleep is also common. Normally, the production of cortisol decreases towards evening and its counterpart, the sleep hormone melatonin, takes over. However, if the release of the stress hormone does not decrease, your body remains on alert. Those affected often have difficulty falling asleep and need more time to recover – which in turn can have a negative effect on your fitness.

Studies ¹ also link stress, lack of sleep, and bering overweight. A constant excess of cortisol shifts your system into a kind of “survival mode”. and all other bodily functions are put on hold for the time being. The consequences can include not only sleep disorders, but also the creation of fat deposits and water retention. 

An overview of possible effects of high cortisol levels:

  • Heart disease
  • Hypertension
  • Difficulty concentrating
  • Memory loss
  • Insomnia
  • Being overweight and problems with weight loss
  • Slower recovery times
  • Performance drop 
  • Compromised immune system

Causes of excess cortisol:

If your cortisol levels are too high, some of the possible reasons might include:

  • Physical stress, e.g. due to excessive workload or overexertion
  • Emotional stress
  • Hypoglycemia
  • Hormonal changes, e.g. due to pregnancy
  • Hyperactivity of the adrenal glands
  • Alcoholism
  • Depression
  • Significant weight gain

What happens if your cortisol levels are too low?

Just like an excess, a lack of cortisol can be harmful to your health. Chronically low cortisol levels should always be treated by a doctor. Very often, they are caused by adrenal conditions

Possible symptoms of cortisol deficiency:

  • Fatigue and weakness
  • Low blood pressure
  • Dizziness or vertigo
  • Irritability, mood swings, and depressive moods
  • High susceptibility to stress
  • Weight loss
  • Gastrointestinal problems
  • Craving for sweets and salty treats

Causes of a cortisol deficiency:

  • Chronically low cortisol levels can have the following reasons, among others: 
  • disease of the adrenal glands, e.g. adrenal insufficiency (Addison’s disease) or adrenogenital syndrome
  • Malfunction of the pituitary gland
  • Certain medications

Reducing cortisol

Stress is now considered the number one most common health problem. A chronic cortisol surplus is not exactly rare in our society. No matter whether you suffer from permanent tension or feel overstrained periodically – you should avoid too much cortisol as much as possible. 

Here are some of the top stress management strategies to keep your cortisol levels at a healthy level:

1. Ensure sufficient rest and recovery

Exercise is healthy and can even reduce stress. But it depends on the amount: too intensive workouts are counterproductive. The brain receives the signal that you have to either escape from a threat – for example during a marathon – or to be ready to fight (“fight or flight”). The result is an increased release of the stress hormone.

Overtraining causes the amount of cortisol to shoot up, so make sure you get enough rest. That means you shouldn’t train every day, and replace the occasional hard workout with a casual jog or bike ride. If you are already very prone to stress, you should be careful with high-intensity workouts such as HIIT. Yoga and meditation are better practices, as they provide peace and balance.

2. Eat a balanced and healthy diet

There’s a reason they say, “You are what you eat.” If you eat a balanced diet, you yourself are more balanced – and less stressed – in everyday life. 

Refined sugar, alcohol, caffeine, and trans-fats (e.g. in chips or french fries) cause your cortisol production to increase rapidly.

Sweets increase your blood sugar levels, and trans fats increase your cholesterol level. Both stimulate the adrenal glands to produce cortisol for regulation. Caffeine also stimulates the adrenal glands to release more of the stress hormone. 

Tip: Replace refined sugar with alternatives such as stevia or xylitol and drink green tea instead of coffee every now and then. Green tea also contains caffeine, but is more easily tolerated by many people. Or try one of our Tea Sets.

In search of healthy, balanced recipe ideas? Take a look at our collection of more than 300 delicious meals.

Image of a balanced salad bowl with eggs, lemon quarter, couscous, carrot sticks, parsley, shredded purple cabbage, beans, goji berries and a tahini sauce. Eating balanced can help reduce your cortisol levels.


3. Make sleep your priority

An excess of cortisol stands in the way of restful sleep. Lack of sleep, problems falling asleep and restless nights in turn fuel your cortisol production – it’s a vicious circle. Therefore, make your night’s rest your priority. 

For example, try taking a melatonin supplement. The sleep hormone is the counterpart to cortisol. The two hormones should always be well balanced.

Also, make sure that your bedroom is cool and dark. Try setting your smartphone or tablet on airplane mode or ‘do not disturb’ at least one hour before going to bed. 

Want more tips? Here are our 8 best tricks for a peaceful sleep


  • Cortisol is a primary stress hormone that is produced under stress in the adrenal cortex to provide energy to the body.
  • In the short term, cortisol can increase performance and concentration, while chronically high cortisol levels are harmful to health.
  • A chronic excess can lead to sleep disorders, heart disease, high blood pressure, weight gain, and concentration problems. 
  • Three major stress management techniques for reducing cortisol levels are exercise and sufficient recovery, healthy eating, and sleep.
  • A cortisol deficiency is also harmful to health and in many cases indicates a malfunction of the adrenal gland, which requires medical treatment.
Article sources
We at foodspring use only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Kim, E. J.; Pellman, B; Kim, J. J. (2015): Stress effects on the hippocampus: a critical review, in: Learning Memory, 22 (9), 411 – 416.

Related Posts