Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA
Quick Answer: What Is Sleep Hygiene?
Sleep hygiene refers to the daily habits and environmental cues that prepare the nervous system for restorative sleep. Effective sleep hygiene supports the shift from sympathetic (“fight or flight”) activation to parasympathetic (“rest and digest”) dominance, allowing cortisol levels to fall and melatonin secretion to rise in alignment with the circadian rhythm (1,10,15).
Core Concept: Sleep Is an Active Biological Process
Sleep is not passive downtime. During sleep, the brain clears metabolic waste via the glymphatic system, tissues undergo repair, and key hormones involved in immune, metabolic, and cognitive health are regulated. Disrupted sleep hygiene interferes with these processes, increasing the risk of fatigue, mood disturbance, insulin resistance, and impaired stress tolerance (4,11,13).
Solution: Evening Rituals That Signal Safety to the Brain
The Evening Wind-Down Ritual
Deep, consolidated sleep depends on consistent pre-sleep signals that communicate safety and predictability to the nervous system.
1. The 8 PM Kitchen Closure
Late or heavy meals increase metabolic activity, body temperature, and cortisol secretion, all of which can delay sleep onset. When hunger is present, a small carbohydrate-containing snack may support tryptophan transport and melatonin synthesis without overstimulating digestion (1,12).
2. Mastering the Light Environment
Light is the dominant regulator of circadian biology.
- Blue light exposure: Evening exposure to screens suppresses melatonin and delays circadian timing. Blue-light filtering software or amber-tinted glasses may reduce this effect when screen use is unavoidable (2,11).
- Red and low-light environments: Warm or red-spectrum lighting in the final 30–60 minutes before bed has minimal impact on melatonin suppression compared with white or blue light (1,2).
3. Temperature and Sleep Environment
A small reduction in core body temperature is required to initiate sleep. Cooler bedroom temperatures (approximately 18–20°C) and complete darkness support normal sleep architecture and melatonin secretion (8,13).
Nervous System Resets for “Wired but Tired” Sleep
Many individuals with “wired but tired” fatigue patterns experience sleep disruption driven by autonomic nervous system hyperarousal rather than sleep pressure alone.
- Herbal teas: Valerian, lemon balm, and passionflower have been shown to modulate GABAergic activity and may support sleep latency and depth in some individuals (2,14).
- Aromatherapy: Lavender exposure has been associated with increased slow-wave sleep and reduced sympathetic activity (1,15).
- Controlled breathing: Slow breathing at approximately 4.5–5 breaths per minute stimulates vagal tone and reduces heart rate variability associated with stress states (15).
- Guided meditation: Structured mindfulness practices can reduce pre-sleep cognitive arousal and improve sleep quality by downregulating limbic activity (1,15).
The Morning Anchor: Setting the Circadian Clock
Sleep hygiene begins on waking. Morning light exposure suppresses residual melatonin and anchors circadian timing, ensuring appropriate melatonin onset the following evening (11,12). Consistent wake times are particularly important in individuals with altered cortisol rhythms or stress-related sleep disruption.
Sleep Saboteurs to Avoid
- Alcohol: Although alcohol may reduce sleep latency, it reliably disrupts REM sleep and increases night-time awakenings (11).
- Late caffeine: Caffeine blocks adenosine receptors, masking accumulated sleep pressure and delaying sleep onset (12).
- Electronic devices: Evening device use combines light exposure and cognitive stimulation, both of which interfere with circadian and autonomic regulation (2,11).
When to Consider Further Investigation
If sleep hygiene strategies improve sleep onset but not sleep maintenance, underlying contributors such as altered cortisol rhythms, thyroid-related sleep disruption, gut dysfunction, or micronutrient imbalance may be involved.
Next Steps
Persistent insomnia despite optimal sleep hygiene warrants a functional assessment of neuroendocrine and metabolic factors influencing sleep. Identifying these drivers allows targeted interventions rather than symptom suppression alone.
Frequently Asked Questions
How long does it take for sleep hygiene changes to work?
Some people notice improvements within days, but full circadian recalibration may take 2–4 weeks of consistent routines.
Is melatonin supplementation the same as improving sleep hygiene?
No. Sleep hygiene supports your body’s own melatonin production, whereas supplementation bypasses regulatory feedback mechanisms.
Why do I fall asleep easily but wake at 2–3 AM?
Early-morning waking is often associated with altered cortisol rhythms, blood sugar instability, or autonomic nervous system activation rather than poor sleep hygiene alone.
Can stress affect sleep even if I feel calm at night?
Yes. Chronic stress can alter nervous system tone and cortisol patterns, disrupting sleep even in the absence of conscious anxiety.
Key Insights
- Consistent sleep and wake times stabilise circadian hormone signalling.
- Darkness, cool temperatures, and reduced light exposure are biological requirements for melatonin release.
- Nervous system regulation is often the missing link in persistent insomnia.
- Sleep disruption may reflect deeper metabolic or endocrine imbalance rather than a primary sleep disorder.
Ready for a Better Night’s Sleep?
If you have implemented evidence-based sleep hygiene strategies and still struggle to stay asleep, there may be an underlying biochemical driver involving stress physiology, gut health, or hormone regulation. A functional assessment can help identify and address the root cause.
Book a discovery call with Rohan Smith at Elemental Health and Nutrition to explore a personalised, evidence-informed approach to sleep restoration.
References
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- Sarris J, Byrne GJ. A systematic review of insomnia and complementary medicine. Sleep Med Rev. 2011.
- Gooley JJ et al. Exposure to room light before bedtime suppresses melatonin onset. J Clin Endocrinol Metab. 2011.
- Chang AM et al. Evening use of light-emitting eReaders negatively affects sleep. PNAS. 2015.
- Czeisler CA. Perspective: casting light on sleep deficiency. Nature. 2013.
- Okamoto-Mizuno K, Mizuno K. Effects of thermal environment on sleep. J Physiol Anthropol. 2012.
- Ebrahim IO et al. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. 2013.
- Reiter RJ et al. Melatonin as an antioxidant. J Pineal Res. 2016.
- Field T. Cortisol decreases following massage therapy. Int J Neurosci. 2005.
- Walker MP et al. Sleep and circadian rhythm disruption and health outcomes. Sleep Med. 2020.
- Wright KP et al. Influence of sleep deprivation on circadian physiology. Proc Natl Acad Sci. 2013.
- Riemann D et al. The hyperarousal model of insomnia. Sleep Med Rev. 2010.
- Vgontzas AN et al. Stress, sleep, and the HPA axis. Sleep Med Clin. 2009.
- Bent S et al. Valerian for sleep: a systematic review. Am J Med. 2006.
- Chien LW et al. Lavender aromatherapy improves sleep quality. J Altern Complement Med. 2012.
