What is Urine Analysis?
A urine analysis is a test that examine the physical, chemical, and the microscopic examination of urine.
It is used to diagnosis in serious disease like kidney disease, liver disease, diabetes and UTI.
Preservation of Urine
Generally urine examined with in 1-2 hrs of collection.
If urine sample is left standing at room temperature for long after collection, following chances occur:-
1) It can causes false results due to growth of bacteria.
2) Increased PH
3) descreased glucose
4) loss of ketone Bodies.
5) lysis of RBC,WBC and Casts.
Urinary Preservatives
1) Toluene
2) Boric acid
3) concentrated hydrochloric acid
4) Thymol
5) Formalin
6) sodium carbonate
7) chloroform
8) Refrigerator - only for 3 - 6 hr
9) freezing - for specimen transport
Physical examinations of urine
1) Volume
2) Colour
3)Odour
4) PH
5) Apperance
6) Specific gravity
1) Volume
The average 24 hrs urinary output in adults is approx 800- 2000 ml.
The volume varies according to fluid intake diet and climate.
Variation in volume of Urine
Polyuria - It means increased quantity of urine .urinary volume more than 2000ml/ hrs.
It seen in diabetes mellitus,diabetes Insipidus, increased water ingestion.
Oliguria - It means decreased quantity of urine. Urinary volume upto or less than 400ml/hrs.
It occurs in febrile states ,acute glomerular nephritis, Dehydration shock.
Anuria
It means total suppression of urine.
Nocturia
It means increased quantity of urine at night.
2) Colour
Normal colour - straw to dark amber.
Pigments responsible for urine colour
Urochrome - yellow
Uroerytrin - Red colour
Urobilin - Orange yellow colour
Clinical significance
Cloudy Red - Hematuria
Clear Red - Hemoglobinuria
Reddish brown - due to porphyrins or urobilinogen.
Brownish yellow/ green - Bile pigments
Milky urine - Chyluria
Black urine - Alkaptonuria
3)Odour
Normal urine is pungent in odour.
Some abnormal Odour of urine with associated conditions:-
1) fruity odour - ketoacidosis
2) Mousy odour - In Phenylketonuria.
3) Fishy odour - UTI with proteins.
4) Foul smell - Bacterial infection .
5) Cabbage odour - In tyrosinemia
4) Apperance or transparency
Normal - clear and transparent
Turbid urine - pus cells , epithelial cells.
Cloudy urine - concentrated urine,UTI, urates,phosphates,uric acid.
Foamy urine - It occurs in the presence of proteins.
5) PH /Reaction
Normal range - 4.6-8
Common - slightly acidic PH 6
vegetarian diet - Alkaline PH
Increased consumption of meat - Acidic PH.
Formed elements are well preserved in acid urine and disintegrated in alkaline urine.
Measured by
Litmus paper
Nitrazine paper
Dipstick
Glass electrode.
6) Specific gravity
Specific gravity measures solute concentration.
Normally specific gravity between 1.015-1.025
A) Increased in
Dehydration ( with oliguria)
Diabetes Mellitus (with polyuria)
Acute renal failure ( with oliguria)
B) Decreased in
Diabetes insipidis
