← Back to discover

THE PURSER WELLNESS REFERENCE

Understand your lab vocabulary.

205 approved laboratory references. Explore the exact ranges, units and context from Dr. Purser’s adult baseline.

16 entries

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Anion gap — lab reference

Formula and albumin correction vary by laboratory. Confirm whether potassium is included.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Blood urea nitrogen (BUN) — lab reference

Protein intake, hydration, catabolism, GI bleeding, and kidney function affect result.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

BUN/creatinine ratio — lab reference

Calculated and context-dependent. Not a stand-alone diagnostic marker.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Calcium, ionized — lab reference

pH and specimen handling materially affect results.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Calcium, total — lab reference

Correct for albumin when appropriate or measure ionized calcium.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Carbon dioxide / bicarbonate — lab reference

Serum chemistry value. Do not substitute arterial blood-gas bicarbonate ranges.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Chloride — lab reference

Interpret with sodium, bicarbonate, and anion gap.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Creatinine — lab reference

Muscle mass, age, diet, medications, and assay matter. Review with eGFR, not alone.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

eGFR, 2021 CKD-EPI — lab reference

G2 60-89; G3a 45-59; G3b 30-44; G4 15-29; G5 <15. G1/G2 alone do not establish CKD without kidney damage.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Lactate, venous — lab reference

Collection method, tourniquet time, exercise, and timing affect result.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Magnesium, serum — lab reference

Normal serum magnesium does not exclude tissue depletion.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Phosphorus — lab reference

Interpret with kidney function, calcium, vitamin D, and PTH.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Potassium — lab reference

Hemolysis can falsely elevate. Review kidney function and acid-base status.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Serum osmolality — lab reference

Measured and calculated values may differ. Review osmolal gap when indicated.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Sodium — lab reference

Volume status, glucose, osmolality, and medications may alter interpretation.

Electrolytes, Renal Chemistry, and Core Metabolic Markers

Uric acid — lab reference

A gout treatment target is not the same as the healthy-population interval.

These pages adapt the Purser educational materials into plain language. They are educational summaries, not individualized assessments or a claim of independent medical review.