dipstick urinanalysis (specific gravity)

Last reviewed 06/2021

Specific Gravity:

  • Urine specific gravity (SG) shows the concentration of urine and represents the hydration status of the patient. Normal specific gravity varies from 1.001 to 1.035

    • increased SG
      • causes include:
          • conditions causing dehydration
            • usefulness of SG in identifying dehydration in infants has been brought into question (2)
          • glycosuria
          • renal artery stenosis
          • heart failure (secondary to decreased blood flow to the kidneys)
          • inappropriate antidiuretic hormone secretion
          • proteinuria

    • some dipsticks give falsely high readings in the presence of dextran solutions and IV radiopaque dyes
      • however this false positive varies with different dipsticks so check the manufacturer's leaflet

    • decreased SG
      • causes include:
        • excessive fluid intake
        • renal failure
        • pyelonephritis
        • diabetes insipidus
        • alkaline urine (eg, a high-citrate diet) may cause false low readings for SG