Thread by @Its_Me_Jasraj

🧵 The Secret Clock Inside You That Controls Sleep, Mood, and Hormones.
Ever felt tired during the day, struggled to sleep at night, or experienced jet lag?
It’s all about your Circadian Rhythm.
Let’s explore how light controls your brain.
👇

Your body runs on a 24-hour internal clock called the Circadian Rhythm.
It controls:
– Sleep and wake cycles
– Hormone release
– Body temperature
– Mental alertness
This rhythm is synced primarily by light.

Meet your body’s master clock: the Suprachiasmatic Nucleus (SCN).
Located in your brain’s hypothalamus, it sits just above your optic nerves.
That means your eyes feed light signals directly to your brain clock.

Here’s the pathway:
Light hits special cells in your eyes →
Activates melanopsin →
Sends signal to SCN →
SCN talks to the PVN →
PVN triggers the spinal cord →
Spinal cord sends signal to pineal gland →
Melatonin is released or suppressed.

Melatonin = Your sleep hormone.
When it’s dark, your pineal gland makes more melatonin → you feel sleepy.
When it’s light, melatonin drops → you feel alert.
Light isn’t just for seeing. It’s your internal timekeeper.

🌅 Morning light is medicine.
Getting sunlight (especially 400–500 nm blue light) early in the day resets your biological clock.
Benefits:
– Boosts mood
– Helps focus
– Sets proper sleep time at night
Start your day outside.

🌃 But light at the wrong time disrupts everything.
– Exposure to screens at night (blue light) blocks melatonin
– Shift work confuses your clock
– Jet lag throws off rhythm
→ Result: Poor sleep, low energy, mood swings, hormone imbalance.

Circadian rhythm disorders are linked to:
– Insomnia
– Depression
– Obesity
– Diabetes
– Heart disease
Your internal clock is not optional - it’s vital for your whole system to work.

✅ How to protect your circadian rhythm:
– Get sunlight within 1 hour of waking
– Avoid screens 1–2 hours before bed
– Dim lights after sunset
– Keep consistent sleep/wake times
– Avoid caffeine late in the day

Your brain and body evolved to sync with the sun.
🌞 Day = Wake, move, eat, think
🌙 Night = Rest, repair, restore
When we fight this ancient rhythm, we pay the price in fatigue, illness, and stress.

TL;DR:
– Light is the master signal of your circadian rhythm
– Morning light heals, night light harms
– Fixing your light habits = better sleep, better life

Follow @Its_Me_Jasraj for more threads on brain health, sleep, and science-backed wellness.

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