Sodium is the main electrolyte outside your cells and plays a central role in fluid balance. Normal range: 136–145 mEq/L.

What this means:

• Low sodium: Usually reflects excess water relative to sodium (not just “low salt”)

• High sodium: Typically indicates dehydration or water loss

Why it matters:

Even mild abnormalities can affect cognition, balance, and overall health.

For healthy individuals:

Small changes are often due to hydration or medications. Persistent abnormalities should be evaluated in context.