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)
- 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
- 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
- causes include:
- increased SG
Reference:
- Whitehead E. Urinarlyis Presentation. East Lancashire HC NHS Trust (2010)
- Steiner MJ, Nager AL, Wang VJ; Urine specific gravity and other urinary indices: inaccurate tests for dehydration. Pediatr Emerg Care. 2007 May;23(5):298-303.