Potassium
Serum potassium is tightly regulated and drifts upward slightly with age, reflecting changes in kidney function, medications, and acid-base status in the population.
Unit: mmol/L · 12 slices · age and sex · 1 source
Filed under panels: Electrolyte Panel · topics: Metabolic , Renal , Electrolytes
Serum potassium is the principal intracellular cation, with serum concentration kept within a narrow range by renal handling, aldosterone, acid-base status, and cellular shifts. It is part of the standard chemistry panel. These percentiles describe the full US adult population from NHANES 2017-March 2020 rather than a screened healthy subgroup.
Population Distribution
Browse by Demographic
| Age (years) | male (mmol/L) | female (mmol/L) |
|---|---|---|
| 20-29 | 3.6–4.6 (4.1) | 3.6–4.5 (4) |
| 30-39 | 3.6–4.6 (4.1) | 3.5–4.6 (4) |
| 40-49 | 3.7–4.6 (4.1) | 3.5–4.5 (4) |
| 50-59 | 3.6–4.8 (4.1) | 3.5–4.6 (4) |
| 60-69 | 3.6–4.9 (4.2) | 3.5–4.6 (4.1) |
| 70+ | 3.6–5.1 (4.3) | 3.5–4.8 (4.1) |
Frequently Asked Questions
Why does potassium drift up with age?
Older adults more often have reduced kidney function, medications that retain potassium such as ACE inhibitors or ARBs, and shifts in acid-base status. That nudges the upper tail of the population distribution upward.
Why is potassium tightly regulated?
Serum potassium has a narrow window that is compatible with normal cardiac and neuromuscular function, so the kidney and cellular uptake work together to keep concentrations stable.
Does hemolysis affect this?
Yes, hemolyzed specimens can falsely elevate measured potassium. NHANES uses standardized collection protocols and quality controls, so population percentiles reflect valid measurements.