All articles
Blood oxygen level explained: what SpO2 and oxygen saturation mean
Blood Oxygen
Melatonin: why the dose matters less than the timing
Circadian rhythm
Heart arrhythmia and palpitations: what a racing, fluttering, or irregular heartbeat means — and when it's dangerous
The pain scale everyone shares: what the McGill chart actually measures
Adrenaline dumps in POTS: what the surge feels like, how long it lasts, and why the next day is worse
POTS & Dysautonomia
HRV monitors: chest strap, wrist wearable, or phone camera — what actually measures heart rate variability
HRV
Why am I bloated all the time? Constant bloating, its causes, and what your gut is telling you
Cortisol
Sarcopenia symptoms: the muscle loss that starts in your 30s, and the two levers that reverse it
HRV
Air hunger and anxiety: why you can't take a deep breath when nothing is wrong
Cortisol
Why do small tasks feel overwhelming? Cognitive overload and the mental load nobody counts
Cortisol
How fast should your heart rate drop after exercise?
HRV
Maximum heart rate by age: why "220 minus age" is wrong (and what to use instead)
HRV