CLUSTER — 9 CAUSES
Metabolic & Hormonal
Brain fog caused by thyroid dysfunction, hormonal shifts, blood sugar instability, and metabolic conditions.
Causes in This Category
Thyroid
Your thyroid sets the metabolic speed of every cell — including neurons. The standard TSH-only test misses up to 50% of thyroid dysfunction. A 2024 Lancet Diabetes & Endocrinology ...
Menopause
Estrogen is neuroprotective — it drives cerebral blood flow, glucose metabolism, and neurotransmitter synthesis. When estrogen drops during perimenopause/menopause, the brain loses...
Testosterone
Low testosterone impairs cognitive function in both men and women. In men: reduces hippocampal function, impairs spatial memory, and increases fatigue. In women: adrenal testostero...
Cortisol
Chronic stress literally shrinks your hippocampus (memory center) and impairs your prefrontal cortex (focus and decision-making). This is structural and measurable on MRI — NOT 'ju...
Pmdd
PMDD is not 'bad PMS.' It's a neuropsychiatric condition where normal hormonal fluctuations trigger abnormal brain responses. Brain fog, concentration failure, and word-finding dif...
Sugar
Blood sugar instability directly impairs cognitive function — both hyperglycemia (glycation damage, inflammatory cascades) and hypoglycemia (brain fuel shortage). You don't need di...
Metabolic Vascular
If you have diagnosed type 2 diabetes, metabolic syndrome, CKD, MASLD/NAFLD, or heart failure — these are PRIMARY medical drivers of brain fog that require guideline-directed treat...
Diabetes
Your brain is a glucose-dependent organ. When blood sugar crashes, your brain starves. The fog hits like a wall — sudden confusion, irritability, inability to concentrate, shakines...
Pcos
Insulin resistance + androgen excess + inflammation = cognitive impairment. The fog that comes with hormonal chaos. PCOS affects 1 in 10 women, and cognitive symptoms are increasin...