Bilateral ureteric obstruction (or unilateral ureteric
obstruction of a solitary functioning kidney).
Retro-peritoneal fibrosis blocking ureteric flow.
ii. Nonobstructive causes:
Mainly produce oliguria:
Inadequate renal perfusion e.g. with vomiting, or diarrhea
will cause depletion of body salts and fluids.
Intravascular volume depletion e.g. with internal
haemorrhage or rapidly developing ascites.
iii. Oliguria with intrinsic renal disease:
Oliguric phase of acute tubular necrosis.
Rapidly progressive glomerulonephritis.
Bilateral cortical necrosis.
End stage renal failure.
Acute nephritic syndrome.
Nephrotic syndrome.
Specific gravity:
Specific gravity represents the amount of solids in urine:
Specific gravity is measured by urinometer or by another special
complicated apparatus which is more perfect (osmometer).
Specific gravity is one of the kidney function tests. In D.I.
repeated measurement of urine specific gravity in face of water
deprivation and after vasopressin administration is mandatory
for proper diagnosis.
