The Longevity Vault

The Longevity Vault

3 Reasons You Keep Waking Up at 3 a.m. After 40 (It's Not Blue Light or Magnesium)

Causes of Midlife Sleep Disruption That Most Doctors Miss

Kat Fu, M.S., M.S.'s avatar
Kat Fu, M.S., M.S.
Mar 18, 2026
∙ Paid

“I haven’t changed anything” same schedule, same bedroom, same everything. So why is my sleep worse?”

I hear some version of this often. Someone in their 40s or 50s whose sleep has gradually gotten worse, and who can’t point to a single thing that’s changed. No new stressors. No obvious cause. Just lighter sleep, more wakeups, less of that deep, restful …

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