Sleep is a fundamental pillar of health, and hormones play a crucial role in regulating it. One such hormone, cortisol, is often associated with stress, but its function extends beyond that. Cortisol helps regulate metabolism, immunity, and the body's sleep-wake cycle. However, when cortisol levels become imbalanced, they can disrupt sleep, leading to poor rest and long-term health issues.
We spoke to Delrina Mohta, Clinical Psychologist and School Counsellor, to understand how cortisol affects sleep. Mohta explains, "Cortisol plays a significant role in regulating your sleep-wake cycle and can profoundly impact sleep quality. Understanding its natural rhythm and how stress affects it can help improve sleep hygiene and overall well-being."
Cortisol’s Natural Sleep-Wake Pattern
Cortisol follows a predictable daily cycle, which is part of the body's circadian rhythm:
- Levels are at their lowest around midnight and begin to rise during the early morning hours.
- A sharp increase occurs in the morning, known as the cortisol awakening response (CAR).
- Peak levels usually occur around 8-9 AM, helping you feel alert and ready for the day.
- Throughout the day, cortisol gradually declines, allowing the body to wind down in preparation for sleep.
- This natural pattern ensures that we wake up feeling refreshed and gradually become tired as bedtime approaches. However, disruptions in this rhythm can negatively impact sleep.
How Cortisol Disrupts Sleep
While cortisol is essential for waking up and staying alert, elevated levels at the wrong times, especially in the evening, can make falling and staying asleep challenging.
High Evening Cortisol
When cortisol remains elevated at night, it can:
- Delay sleep onset – making it difficult to fall asleep.
- Reduce deep sleep – particularly slow-wave sleep (SWS), which is essential for physical and cognitive recovery.
- Increase night-time awakenings, leading to fragmented sleep.
- Shorten total sleep duration, leaving you feeling groggy and unrefreshed in the morning.
Disrupted Cortisol Rhythms and Sleep Disorders
Various factors can throw off the body’s natural cortisol rhythm, leading to sleep disturbances:
- Chronic stress – Prolonged stress increases cortisol levels, keeping the brain in a hyperactive state.
- Shift work – Irregular work schedules can disrupt circadian rhythms.
- Jet lag – Travelling across time zones alters cortisol patterns, leading to sleep difficulties.
- Depression and anxiety – Mental health conditions can dysregulate cortisol production, worsening sleep quality.
- Sleep apnea – Repeated awakenings during sleep can trigger excessive cortisol release.
- Cushing’s syndrome – A rare condition characterised by excessive cortisol production, often leading to severe insomnia.
The Vicious Cycle of Cortisol and Poor Sleep
Lack of sleep itself can further increase cortisol levels, creating a harmful cycle:
- Stress raises cortisol.
- High cortisol disrupts sleep.
- Poor sleep increases cortisol production even further.
- This cycle continues, making it harder to restore a normal sleep pattern.
Delrina Mohta highlights, "If this cycle is not addressed, it can lead to chronic insomnia, anxiety, and even increased risk of metabolic disorders like diabetes and hypertension."
How to Manage Cortisol for Better Sleep
Balancing cortisol levels is essential for improving sleep quality. Here are some expert-recommended strategies:
- Maintain a consistent sleep schedule – Going to bed and waking up at the same time every day helps regulate cortisol production.
- Practice relaxation techniques – Meditation, deep breathing, and progressive muscle relaxation can lower stress-induced cortisol spikes.
- Exercise regularly – Physical activity helps regulate cortisol, but avoid intense workouts close to bedtime.
- Create a calming bedtime routine – Engaging in relaxing activities like reading or listening to soothing music can signal your body to wind down.
- Limit screen exposure before bed – Blue light from screens can suppress melatonin (the sleep hormone) and increase cortisol levels.
- Avoid caffeine late in the day – Caffeine stimulates the nervous system and can elevate cortisol levels at night.
- Consider adaptogens – Certain herbs, like ashwagandha and rhodiola, may help the body regulate stress and cortisol levels naturally.
When to Seek Medical Advice
If sleep issues persist despite lifestyle changes, it may be a sign of an underlying medical condition affecting cortisol regulation. Consulting a healthcare professional can help identify and address potential causes, such as adrenal disorders or chronic stress conditions.
Mohta advises, "Persistent sleep difficulties should not be ignored. Seeking professional help can prevent long-term health consequences associated with cortisol imbalance and sleep deprivation."
Conclusion
Cortisol is a vital hormone for maintaining energy and focus, but when it becomes dysregulated, it can have a detrimental effect on sleep. By understanding its natural cycle and taking steps to manage stress, you can enhance sleep quality and overall well-being. If sleep issues persist, professional guidance is recommended to rule out any underlying health concerns.