Cortisol Levels: How Much Of This Stress Hormone Is Healthy?

When researching stress online, you’ll probably run into many mentions of one particular molecule: cortisol. This steroid hormone helps control various biological processes, including the body’s response to challenging or alarming situations.  

You can likely find countless articles suggesting ways to lower the amount of this “stress hormone” in your blood. But what are typical cortisol levels, and what exactly happens if you have overly low or overly high levels of cortisol in your system? 

Cortisol levels in the bloodstream usually vary in a predictable rhythm throughout the day, though they can be dramatically elevated in response to situations that provoke fear or anxiety. Consistently high levels of cortisol may have a host of unwanted health effects, including obesity, anxiety, depression, high blood pressure, and heart disease.  

Having too little cortisol can also be dangerous, resulting in symptoms like fatigue, pain, loss of appetite, and low blood pressure. Understanding what controls cortisol levels and how it affects your body could help you better monitor your mental and physical health. 

How your body generates cortisol 

Cortisol is a type of steroid hormone called a glucocorticoid. These are signaling molecules that function within a complex regulatory system controlling many different biological processes throughout the human body, including metabolism, immune function, and cardiovascular activity. 

The adrenal glands, located on top of the kidneys, synthesize cortisol from cholesterol and release it into the bloodstream. Production of this hormone is controlled by the hypothalamic pituitary adrenal (HPA) axis.  

This system links the adrenal glands with the hypothalamus and pituitary gland within the brain. High activity in the HPA axis often involves the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, which signals the adrenal gland to make more cortisol. 

The HPA axis generally shifts its activity up and down based on the day-and-night cycle, but release of the adrenocorticotropic hormone (ACTH) from the pituitary gland and, in turn, cortisol from the adrenal glands can also be activated in response to various forms of physical and mental stress, including exercise, infections, fear, and trauma. 

These stressors tend to increase the activity of the adrenal glands, causing cortisol levels in the bloodstream and saliva to increase. This is why cortisol is often referred to as a stress hormone: High concentrations of this molecule may indicate that a person or animal is under some type of strain. 

What are typical cortisol levels? 

If you’re interested in finding out whether your cortisol levels are healthy, you can consult with a physician. Because this steroid hormone can fluctuate dramatically in response to many kinds of stimuli, it can be hard to interpret the results of a cortisol test without professional training. 

What effects does cortisol have in the body? 

Increased cortisol levels can lead to a number of biological shifts, including the following: 

Metabolic changes 

Cortisol plays a large role in controlling the way your body processes fats and sugars. A surge in this hormone often triggers an increase in blood glucose, possibly to give you a boost of energy to deal with a threatening situation. In the short term, this can lead to a breakdown of fatty tissue to supply you with fuel. 

However, there are indicators that consistently high cortisol levels in the circulatory system can be linked with unwanted weight gain and obesity. These metabolic changes can lead, in turn, to other health consequences, such as an increased risk of cardiovascular disease. 

One possible explanation is that cortisol exposure tends to increase the appetite for sugary, fatty, and salty foods. Repeated surges of cortisol may also cause higher levels of blood sugar, which can lead to insulin resistance over time.  

As the body gets less sensitive to insulin, it may be slower to remove glucose from the bloodstream, leading to more accumulation of fat.  

In extreme cases, having too much cortisol in your system for too long may result in a breakdown of muscle tissue. This can happen when you run low on the raw materials to make glucose. In response to continued cortisol signaling, the body may start consuming muscle tissue to fuel glucose production. 

Immune suppression 

Cortisol usually has a calming effect on the immune system. It typically decreases the activity of cells that cause tissue inflammation in response to problems like infections and injuries. This helps to prevent excessive immune activity that could damage the body. 

However, when cortisol levels remain too high for too long, the immune system may become desensitized to this hormone. This can lead to chronic inflammation, which may have negative effects throughout the body. Possible effects could include heart disease, gastrointestinal problems, decreased fertility, and chronic pain. 

Brain changes 

Cortisol may be involved in the storage of memories, particularly those associated with emotionally significant events. Studies indicate that this response changes with dosage: Low and moderate levels of cortisol seem to improve memory performance, while higher levels may impair it. Other cognitive functions, like decision-making and language fluency, also seem to decrease in response to high cortisol. 

In the long run, these effects may be linked to changes in the structure of the brain. Prolonged exposure to cortisol may shrink regions like the hippocampus, amygdala, and frontal lobe. This can mean that levels of cortisol that are too high may increase the risk of dementia and other kinds of unhealthy aging. 

These alterations to the brain might also play a role in the development of mental health conditions like depression, anxiety, and bipolar disorder. There’s some evidence that long-term exposure to high cortisol levels can lead to many of the symptoms of these conditions. 

What can cause high cortisol levels? 

Chronic stress can be a significant driver of increased cortisol secretion. Individuals under long-term mental and emotional strain may have an extended HPA axis response, causing cortisol levels to remain high for longer than usual. This means that chronic stress can be a risk factor for the negative effects of a high cortisol level as described above. 

Excessive cortisol may also result from physical causes. For example, a tumor on the pituitary gland might trigger the overproduction of adrenocorticotropic hormone, leading to the creation of more cortisol. A tumor on the adrenal gland can cause the same effect more directly. Some people may also develop symptoms of excess cortisol due to overuse of synthetic steroids.  

People with an extremely high level of cortisol may develop a condition called Cushing syndrome. Symptoms of Cushing syndrome can include: 

• High blood pressure 

• Weight gain in the abdomen and face 

• A distinctive lump of fat between the shoulder blades 

• Weakened bones 

• Muscle weakness 

• Acne 

• Vividly colored stretch marks 

Too little cortisol can also be a problem 

Abnormally low cortisol levels can also lead to some characteristic health difficulties. This condition is known as adrenal insufficiency, and signs can include: 

• Low blood sugar 

• Low blood pressure 

• Weakness, fatigue, and dizziness 

• Nausea, vomiting, and diarrhea 

• Lack of appetite 

• Weight loss 

• Dehydration 

There are two main types of low cortisol disease: 

1. Primary adrenal insufficiency, also known as Addison’s disease, which is a rare condition in which the adrenal glands are damaged by an autoimmune response. As a result, they can no longer produce enough cortisol and aldosterone to maintain proper health. Addison’s disease is often marked by darkened skin, with bruise-colored discoloration around areas like the genitals, rectum, nipples, and mouth. 

2. Secondary adrenal insufficiency results from other kinds of disruptions to the HPA axis, such as pituitary gland tumors. This can lead to the underproduction of adrenocorticotropic hormone, depriving the adrenal gland of the signal to make cortisol. 

In severe cases, adrenal insufficiency can lead to severe pain, kidney failure, shock, and even death. Consult a doctor if you're experiencing symptoms of any medical condition. 

How can you balance your cortisol levels? 

Since diseases affecting cortisol production are rare, taking steps to manage chronic stress is often the most effective way to keep this hormone under control. Effective ways to lower your stress levels may include: 

• Eating nutrient-dense foods as often as possible 

• Getting regular physical exercise 

• Maintaining a healthy sleep schedule 

• Practicing meditation 

• Spending time outdoors and with other people 

• Limiting your intake of tobacco, alcohol, caffeine, and other substances 

• Talking to your doctor about ways to control high blood pressure 

• Speaking with a licensed, trained psychotherapist 

If you are struggling with substance use, contact the SAMHSA National Helpline at (800) 662-4357 to receive support and resources. Support is available 24/7. 

Therapy for stress management 

If you want to get help from a mental health professional for your feelings of strain and stress, you may want to try online therapy. This might be particularly helpful for individuals with many demands on their time—which often describes those experiencing chronic stress. With an online therapist, you can receive therapy without leaving your home, which may make it easier to find the time for treatment. You can connect with a therapist in a way that’s most comfortable for you, whether by audio, video, or in-app messaging. 

Internet-based therapy has been repeatedly studied and suggested to be effective for many kinds of psychological challenges, including stress. For example, one study indicates that online cognitive behavioral therapy delivered over the web produced significant reductions in various stress-related symptoms.