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Sleep is essential for well-being, and cortisol plays a key role in regulating alertness and the sleep-wake cycle.
High cortisol levels can disrupt the production of melatonin, the hormone responsible for regulating sleep, and lower adenosine levels, which play a role in promoting sleepiness.
Sleep, a vital aspect of overall health, is influenced by a complex interaction of hormones and biological rhythms. One of the most significant hormones in this process is cortisol, commonly referred to as the stress hormone. It plays a crucial role in regulating the sleep-wake cycle and maintaining alertness during the day.
Produced by the adrenal glands, cortisol follows a natural 24-hour rhythm, rising in the morning to promote wakefulness and gradually declining in the evening to support relaxation. However, disruptions caused by stress, lifestyle factors, or sleep disorders can interfere with this cycle.
According to The Indian Express, Dr Yatin Sagvekar, Consultant Neurologist at Kokilaben Dhirubhai Ambani Hospital in Navi Mumbai, emphasised the strong link between cortisol regulation and sleep quality. He highlighted that maintaining a balanced cortisol rhythm is essential for overall health and optimal sleep patterns.
The Cortisol Cycle: How It Affects Sleep
When cortisol levels are elevated, they interfere with the production of melatonin, the hormone responsible for signalling sleep, and reduce adenosine, a molecule that builds up throughout the day to create sleep pressure. Cortisol follows a natural daily rhythm, reaching its highest point in the morning, typically around 8 AM. The hormone begins increasing in the early morning hours to help the body transition from sleep to wakefulness. As the day progresses, cortisol gradually declines, reaching its lowest level around midnight, which aligns with the body’s natural urge to rest.
This cycle ensures that we stay alert and active during the day while allowing for deep, restorative sleep at night. However, disruptions to this pattern—caused by chronic stress, poor sleep habits, or medical conditions—can lead to sleep disturbances and long-term health complications.
The HPA Axis: Its Influence On Sleep Patterns
Cortisol production is controlled by the hypothalamic-pituitary-adrenal (HPA) axis, which slows down in the evening to prepare the body for sleep. However, if the HPA axis becomes overactive due to stress, irregular sleep routines, or conditions like obstructive sleep apnoea (OSA), it can disturb this delicate balance.
- Overactive HPA Axis And Insomnia: Chronic stress can overstimulate the HPA axis, leading to sleep fragmentation and persistent insomnia.
- Excess Cortisol And Sleep Deprivation: When sleep is consistently disrupted, cortisol levels remain elevated, negatively affecting sleep architecture and overall health.
As reported by The Indian Express, Dr Sagvekar emphasized that prolonged lack of sleep and an overactive HPA axis can contribute to obesity and type II diabetes. Elevated cortisol levels disrupt insulin function and glucose regulation and heighten the risk of metabolic disorders. Additionally, cortisol’s immune-suppressing effects can reduce the body’s ability to fight off infections.
Cortisol, Hormonal Imbalance And Menopause
Consistently high cortisol levels can also disrupt hormonal balance, particularly in women. Excess cortisol suppresses estrogen, leading to symptoms that mimic menopause, such as mood swings, night sweats, disrupted sleep and increased fat accumulation around the midsection.
For women already experiencing menopause, sleep disturbances may be even more pronounced. The hormonal shifts during this phase often lead to increased stress, anxiety and depression, all of which further elevate cortisol levels. Research indicates that cortisol tends to remain higher at night during menopause and it can spike immediately after a hot flash. This heightened state of alertness makes it even more difficult to fall and stay asleep.
Tips for Maintaining a Healthy Cortisol Balance and Better Sleep:
- Stick to a regular sleep schedule by going to bed and waking up at the same time every day.
- Create a relaxing nighttime routine by reducing screen time, dimming the lights and minimizing exposure to stimulating activities.
- Practice stress management techniques such as meditation, deep breathing exercises, or gentle yoga to lower cortisol levels.
- Avoid caffeine and heavy meals before bedtime to prevent unnecessary stimulation that could interfere with restful sleep.
