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Sleep Architecture
Foundational to every other system
Sleep duration, regularity, depth, and light timing form the circadian foundation. Poor sleep cascades through every other environment in your body.
What it needs
- 7–9 hours for most adults
- Consistent sleep/wake times
- Dark, cool sleeping environment
- Morning light exposure
- Limited evening blue light
What wrecks it
- Irregular schedule (social jet lag)
- Evening caffeine or alcohol
- Light pollution at night
- Chronic stress and rumination
- Shift work without mitigation
Indicators to observe
- Total sleep time (hours)
- Sleep onset latency
- Wake-after-sleep-onset
- Morning alertness
- Weekend vs weekday drift
What the evidence shows
UK Biobank and NHANES data consistently show U-shaped mortality curves for sleep duration. Severe insomnia associated with ~3 year mortality modifier in pooled analyses.
Open questions
- Optimal sleep duration by age and sex
- Nap timing and cardiovascular effects
- Sleep tracker accuracy vs clinical polysomnography