Cortisol And It’s Effect On Sleep: Sleep Stages And Effects

Cortisol And Sleep

Cortisol And Sleep

In this article, we will discuss how cortisol and sleep effects on health.

Sleep, breathing, and consuming food and water is an essential requirement for keeping up the body’s normal functioning. Survival abilities may rely entirely on how much sleep a person gets daily.

Stress has a powerful influence on an individual’s lifestyle. It increases the production of a hormone called cortisol, which plays a vital role in the body’s sleep-wake cycle.

What is Cortisol?

Cortisol is a hormone that is produced by the hypothalamic-pituitary-adrenal (HPA) axis/gland. This system includes the hypothalamus and the pituitary gland, which are present in the brain. The adrenal glands are located above the kidneys. 

When stressed, the brain activates this system to produce hormones that eventually make the adrenal glands secrete cortisol. The whole process is a complex and sensitive feedback loop with hefty effects in the body, mind, and sleep.

Effects of Cortisol on Health

The body’s primary stress hormone is cortisol. It is a highly stimulating and alerting substance. Since every cell is equipped with cortisol receptors, it can trigger various instant threat responses. It drives the body’s flight-or-fight response against the presence of a threat or stressor.

Some of its other functions include:

  1. Regulating blood sugar
  2. Balancing blood pressure
  3. Promoting inflammation symptoms
  4. Regulating energy
  5. Aiding the sleep-wake cycle

Inherently, cortisol is an essential component of human physiology. Small spurts of cortisol released under short durations motivate the mind and give the body a physical boost. But chronic stress can lead to elevated levels of the hormone, thus giving rise to health issues like:

  1. An escalation of all its functions leads to high blood sugar and pressure, uncontrolled inflammation, unnecessary energy production, and breathlessness.
  2. These can lead to chronic illnesses like diabetes and heart diseases.
  3. Digestive system complications that include heartburn, stomach ulcers, and constipation.
  4. The appetite may also be triggered unnecessarily due to hormonal changes, leading to binge-eating and weight gain.
  5. Nutrients are absorbed at a controlled rate.
  6. Increases the risk of brain fog.
  7. Mood disorders, like depression and anxiety.
  8. Fatigue and sleep disorders.

Cortisol and Sleep

The HPA axis is shared by both sleep and stress response. If the levels rise, the axis’ functioning is hindered, causing sleep to be affected. here is a detailed analysis of the same:

Sleep-wake Cycle:

The human body is synchronized with daytime and night-time, allowing a balanced sleep-wake cycle within 24 hours. This regulation is known as the circadian rhythm. In other words, it can be described as the body’s natural clock.

Cortisol also follows a similar circadian rhythm. The lowest level of this hormone is produced at midnight, while the production peaks at least an hour after waking up. Usually, the peak occurs at around 9 am. 

Throughout the day, 15 to 18 pulses of cortisol are sent out for regular working. These spurts may adjust according to the individual’s sleep schedule since they naturally lower their secretion during bedtime.

Sleep Stages:

The body goes through various stages of sleep throughout the night. They are:

1. Stage – 1

This is the shift from wakefulness to sleep. It can prove to be the most challenging stage to overcome, since stress may fight off the body’s need to start drifting off to sleep. Heightened cortisol and adrenaline do not provide the relaxation needed for this stage to be successful.

2. Stage – 2

The muscles relax, the breathing gets shallow, and the heartbeat slows down. A chronic state may continue keeping the muscles tense. The breathing and heart rate are also unregulated, leading to a semi-sleep state, which can be quickly interrupted.

3. Stage – 3

Also known as the ‘slow-wave sleep’, it is the deepest stage of sleep. The body is almost unresponsive to disturbances and may enter a state of loosely-bound paralysis.

However, the body’s stressed state would make the person wake up repeatedly throughout the night. It is almost improbable for them to attain deep sleep.

4. Stage – 4

It is the only stage of rapid-eye-movement (REM) sleep, where the eyes scurry when the eyelids are closed, in response to the dreams taking place. It does not include the movement of the other parts of the body.

But a chronically stressed person may respond to those dreams violently, resulting in them waking up. Their REM sleep may be characterized by the thrashing of the limbs, sleep talking, and even eye movement.

Tips for Better Sleep

Controlling cortisol levels is crucial for better sleep. This means that there is a need for stress management, which would automatically regulate the cortisol secretion. The circadian rhythm of sleep would resume, and there would be lesser factors that contribute to a night of disturbed sleep.

Following healthy habits and stress-relieving practices may help the individual, without the need for seeking medicines. Some of the tips we suggest are:

Eating Habits:

The diet should be clean of binge-eating habits. While hormonal changes may compel the individual to disregard proper meal times and healthy food options, certain items may contain substances that influence cortisol production.

Products that should be limited or avoided altogether, are:

    1. Meat-based proteins
    2. Refined sugar
    3. Salt and sodium-products
    4. Fats, especially trans and unsaturated fats
    5. Caffeine-related items like coffee and energy drinks

Managing Stress:

Since the presence of stress heavily influences cortisol, some tips to control the risk of chronic levels are:

Stress Mediating Activities

These include meditation, yoga, aromatherapy, and other means of relaxing the body.


Physical activities nurture the production of feel-good hormones and also tire the body out for bedtime. Moderate levels of activities a few hours before bed are enough to have positive effects.

Identify the Causes

Usually, a person stresses unnecessarily over things that can be planned out. Search and solve the causes of stress. This gives a sense of control, leading to a reduction in tension.

Unwind the Mind and Body

Choose to do activities other than those related to work or heavy socializing. Indulging in a hobby, spending time with pets, napping for a maximum of 20 minutes, etc. are some tasks for which the brain does not need to strain itself.

Talk it out

Bottled up stress may send the cortisol levels into haywire. It has the potential of causing other mental disorders like depression and anxiety. Communicating worries to loved ones or taking help from a friend may help ease the burden.


In the long run, sleep deprivation may degrade one’s lifestyle and prove to be fatal with the rise of various illnesses. Talk to a doctor about regulating cortisol levels, if self-help methods fail to give a good night’s sleep. The individual may be asked to incorporate medication and therapy with various lifestyle changes, to ensure healthy sleep.