Sleep Health

Why Am I Always Tired? 10 Hidden Causes

Persistent fatigue is rarely about willpower. These are the most common — and most fixable — root causes.

January 26, 20267 min readSleep Health

Undiagnosed sleep apnea

Loud snoring plus daytime sleepiness warrants a home sleep test.

Iron, vitamin D or B12 deficiency

Three of the most common deficiencies behind chronic fatigue. A simple blood panel can identify them.

Poor sleep efficiency

Spending 9 hours in bed but only 6.5 asleep means your real sleep is well below the 7-hour minimum.

Hidden dehydration

Even mild dehydration reduces alertness and increases perceived effort during the day.

Mental load and burnout

Sustained chronic stress depletes the same energy systems that sleep is meant to restore.

Editorial standards

Last reviewed January 2026 against current US sleep medicine guidelines by the Sleep Disorder Symptoms editorial team. This article is educational and is not medical advice — see our medical disclaimer and editorial policy.

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