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Dear health-conscious friends,

​If you find it strangely easy to scroll TikTok at midnight but strangely difficult to fall asleep afterwards, you are not alone. Modern screens are fantastic at keeping our brains awake long after our bodies would prefer to be asleep. Here is what is actually going on and what to do about it, without moving to a cabin in the woods.

The light problem: blue light and melatonin
The first issue is physics. Screens emit a high proportion of blue wavelengths, which signal to the brain that it is daytime. Your brain responds by suppressing melatonin, the hormone that makes you feel drowsy and helps coordinate the sleep-wake cycle. Less melatonin means a harder time falling asleep and staying asleep.

But blue light is only half the story.

The reward problem: the dopamine loop
Even if your screen emitted the gentlest candlelight hue, the content itself would still keep you awake. Social media apps, news platforms, and streaming services are engineered to trigger small dopamine rewards that encourage continued engagement. This keeps the brain in a state of heightened attention rather than the low-arousal state needed for deep sleep.

The rhythm problem: circadian misalignment
Your body keeps time using an internal 24-hour clock. Light, food timing, exercise, and temperature all give it cues. Late-night screen exposure shifts those cues, telling your internal clock that bedtime is later than it is. Over weeks or months, this creates a chronic misalignment between when you want to sleep and when your brain thinks sleep should happen.

How to fix it (without pretending screens don’t exist)
Banning screens entirely after 6 PM is unrealistic for most people. Fortunately, smaller interventions work surprisingly well.

1. Screen curfew
   Set a cutoff 60 to 90 minutes before bed for phones, laptops, and TVs. If that sounds extreme, start with 30 minutes and work upward.
2. Filter the light
   Use night mode or blue light filters in the evening. Physical blue-light-blocking glasses can also help. They do not eliminate the problem, but they drastically reduce light-driven melatonin suppression.
3. Change the content
   Swap stimulating content (doomscrolling, gaming, action TV) for passive or predictable content (audiobooks, documentaries, calm shows). Your brain does not need cliffhangers at 23:47.
4. Use a paper buffer
   Instead of scrolling in bed, read a physical book for 10 to 20 minutes. This is an easy way to transition the brain out of reward mode and into sleep mode.
5. Target your circadian anchors
   These are powerful and often underestimated:
   • morning sunlight for 10 minutes after waking
   • regular meals
   • consistent sleep-wake timing
   • evening dim lights

These send your internal clock the information it needs to make sleep easier at night.

If you have tried all of the above and still wake feeling unrefreshed or fatigued, issues such as sleep apnea, medication side effects, thyroid disorders, or depression may be worth evaluating with a doctor.

Want more content like this? Check out our Youtube channel Askadoc! (below)

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👩‍⚕️ Dr. Joanna​
​AskADoc4Advice — where medicine meets curiosity (and a little bit of weird).

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