Normal urine composition and the physiology of urinalysis
Normal urine volume, osmolality, pH and protein, what each dipstick pad really detects, what casts and crystals mean, and how to calculate and interpret the fractional excretion of sodium.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Normal adult urine output is about 0.8 to 2 L/day, with an osmolality anywhere from 50 to 1,200 mOsm/kg depending on ADH.
- Normal total protein excretion is under 150 mg/day, and albumin under 30 mg/day. The most abundant normal urinary protein is uromodulin (Tamm-Horsfall protein), made in the thick ascending limb.
- Glucose appears when the filtered load exceeds the tubular maximum, at a plasma glucose of about 10 mmol/L in a healthy adult.
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Sources
- Chronic kidney disease (CKD) management in primary care (5th ed.)AU/NZKidney Health Australia, 2024 (current edition, checked November 2026)
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney DiseaseKidney International 2024;105(4S):S117-S314, 2024
- Brenner and Rector's The Kidney (11th ed.)Elsevier (Yu, Chertow, Luyckx et al., 2020), 2020
- Guyton and Hall Textbook of Medical Physiology (14th ed.)Elsevier (Hall and Hall, 2021), 2021
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy