Heart & nervous system
Understand what your heart rate, rhythm, and recovery reveal about your health — and what keeps your heart and nervous system resilient.
Most read
August 11, 2026
What is a good HRV? An HRV chart by age and sex, and how to read your own number
There's no single good HRV number — it depends on your age, sex, and above all your own baseline. Rough RMSSD ranges by age, why comparing to others is meaningless, and how to actually tell if your HRV is healthy: your baseline and your trend.
September 14, 2026
How to Increase Blood Oxygen Level: Healthy Habits — and When Low Oxygen Means You Need a Doctor
Everyday habits that support breathing and circulation for healthy people — and the clear line where a low oxygen reading stops being a wellness goal and becomes a medical issue.
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Latest articles
Low blood oxygen (hypoxemia): symptoms, causes, and when to worry
September 14, 2026
How to Increase Blood Oxygen Level: Healthy Habits — and When Low Oxygen Means You Need a Doctor
September 14, 2026
Pulse oximeter: how it works, how accurate it is, and what wearable SpO2 really tells you
September 14, 2026
What Is a Normal Blood Oxygen Level? SpO2 Ranges Explained
September 14, 2026
Heart arrhythmia symptoms: what an irregular heartbeat can feel like
September 14, 2026
Atrial fibrillation treatment — stroke prevention, rate and rhythm control, and lifestyle
September 14, 2026
How to treat heart arrhythmia and stop heart palpitations
September 14, 2026
Midodrine Uses and How Drug Interactions Work: A Plain-Language Guide to Asking the Right Questions
September 14, 2026
Does summer heat affect your blood pressure? What warm weather, dehydration, and your medications really do
September 14, 2026
How accurate is HRV from a phone camera?
September 12, 2026
Nervous system snapshot
September 12, 2026
Measure HRV without a wearable
September 12, 2026
What is an EKG (ECG)? How a heart test reads your heart's electrical activity
September 6, 2026
Personalized heart rate zones: why your diagnosis, medications, blood work, and daily life decide what the numbers mean
August 25, 2026
Atrial fibrillation (AFib): what it is, symptoms, stroke risk, and when to see a doctor
August 21, 2026
Exertional dyspnea: why you get short of breath on exertion — from deconditioning to the signals that matter
August 18, 2026
Why are my hands always cold? Five causes on the spectrum from normal to worth checking
August 18, 2026
Why is my heart racing at night? What a pounding heart at bedtime actually means
August 18, 2026
Heart rate variability meaning: what HRV measures and what it doesn’t
August 16, 2026
Heart rate variability: what HRV measures, what affects it, and how to read your numbers
August 16, 2026