Always Tired, Foggy, or Lightheaded? 8 Possible Reasons Why
Alicja Sundblade, FNP-CPublished on: 08/10/2026
Feeling constantly tired, foggy, or lightheaded? Explore 8 possible causes—from nutrient deficiencies and thyroid health to hormones, sleep, hydration, blood sugar, and POTS—and learn what patterns may offer helpful clues.
Fatigue and brain foglightheadednesscause of fatiguebrain fog causeschronic fatigueiron deficiencythyroid healthblood sugar regulationperimenopause and fatiguepoor sleep and fatiguedehydration and dizzinessorthostatic intolerancePOTSWomen's healthfunctional medicine