ABNORMAL URINE
Physical characteristics of abnormal urine:
1. Volume:
Polyuria > 3 L/day Oliguria < 400 ml /day Anuria < 100 ml/day
Diabetes mellitus, Diabetes insipidus Fever, diarrhea Hypovolemic shock
2. Appearance: Turbid
UTI, Chyluria.
3. Odour :
Fruity odour - Ketoacidosis due to ketone bodies Burnt sugar smell- Maple Syrup Urine Disease
Mousy odour- Phenylketonuria Foul smell- Bacterial infection
4. Specific gravity:
Increased : Diabetes mellitus, Nephrotic syndrome.
Decreased : Diabetes insipidus, High fluid intake
ABNORMAL URINE
Physical characteristics of abnormal urine:
5. Color
Color Metabolite Clinical condition
RBC (Hematuria) Renal calculi, Acute
Red Glomerulonephritis,
Incompatible blood
Hb (Hemoglobinuria) transfusion
Bilirubin Hepatic Jaundice
Yellow green Biliverdin Obstructive Jaundice
Brown black Homogentisic acid Alkaptonuria
Milky white Chyle (Chyluria) Filariasis,
6.pH: Acidic- Diabetic ketoacidosis, Alkaline -Diet rich in vegetables and fruits
Respiratory and Metabolic alkalosis
ABNORMAL URINE
Commonly encountered pathological constituents of urine:
1. Reducing sugar:
a) Glucose (Glycosuria) : Diabetes mellitus, renal glycosuria.
Normal renal threshold for glucose :175 - 180 mg/dL,
b) Lactose (Lactosuria) : Third trimester of pregnancy, lactation.
c) Galactose (Galactouria) : Galactosemia.
d) Fructose (Fructosuria) : Hereditary Fructose intolerance.
e) Pentose (Pentosuria) : Essential Pentosuria.
Non-carbohydrate reducing substances: Ascorbic acid, Homogentisic acid, salicylates,
glucuronides of drugs
ABNORMAL URINE
Commonly encountered pathological constituents of urine:
2. Ketone bodies
Acetoacetic acid, beta hydroxy butyric acid and acetone - Liver.
Clinical significance:
Ketonuria in severe uncontrolled Diabetes mellitus and starvation
3. Proteins ( < 150 mg/ day)
Clinical significance:
• Albumin:
Physiological causes : Strenuous exercise, pregnancy
Pathological causes : Nephrotic syndrome, Chronic Glomerulonephritis
• Bence Jones proteins : Multiple Myeloma
Microalbuminuria: Urinary albumin excretion in range of 30 - 300 mg/day.
4. Blood
Clinical significance : Hematuria, Hemoglobinuria
ABNORMAL URINE
Commonly encountered pathological constituents of urine:
5. Bile salts
Bile acids from cholesterol.
Primary bile acids : Glycocholic acid, Tauro cholic acid, Glycochenodeoxy cholic acid and
Taurochenodeoxy cholic acid.
Secondary bile acids : Deoxycholic acid and Lithocholic acid.
Bile salts : Sodium or potassium taurocholate and sodium or potassium glycocholate.
Bile salts - Emulsifying agents, help in digestion of lipids.
6. Bile pigments
Bile pigments - breakdown products of heme.
Biliverdin and bilirubin are the bile pigments.
Clinical significance:
Obstructive jaundice: Gall stones, Carcinoma of head of pancreas,
lymph node enlargement in porta hepatis.
REACTIONS OF ABNORMAL URINE
1. REDUCING SUGAR:
a. Benedict’s test:
.
Principle: Benedict’s reagent contains
Copper sulphate - provides cupric ions in solution
Sodium carbonate - provides an alkaline medium
Sodium citrate - prevents the precipitation of cupric ions
The sugar under alkaline conditions tautomerises to form an enediol. This reduces cupric ions to
cuprous ions, which accepts OH group from the solution to form cuprous hydroxide.
This on heating is converted to cuprous oxide, which gives a color varying from green to red
depending on the concentration of sugar. Hence, it is known as semi quantitative test.
Approx conc. of sugar in urine
Color of the precipitate (gm%)
Green (+) 0.5 g%
Yellow (++) 1.0 g%
Orange (+++) 1.5 g%
Red (++++) 2.0 g%
REACTIONS OF ABNORMAL URINE
2. KETONE BODIES:
a. Rothera’s test: Principle
Nitroprusside in alkaline solution reacts with a keto group to form a purple ring.
3. PROTEINS
a. Heat coagulation test: Principle
Albumin, being a heat coagulable protein, answers the test. The appearance of coagulation
indicates denaturation of proteins and addition of acetic acid precipitates protein. On the other
hand, if the coagulum disappears on addition of acetic acid, it indicates the precipitation is
due to phosphates
3. PROTEINS
b. Sulphosalicylic acid Test : Principle
Proteins are amphoteric in nature, i.e. they behave as acids in alkaline medium and as bases in an
acidic medium. In the presence of sulphosalicylic acid, they act as bases, and react with the acid
to form an insoluble salt of protein sulphosalicylate.
4. BLOOD (OR) HAEMOGLOBIN:
a. Benzidine Test: Principle:
Heme part of hemoglobin has peroxidase like activity which releases nascent oxygen from
H2O2 . This nascent oxygen oxidizes Benzidine to form a transient green colored compound.
REACTIONS OF ABNORMAL URINE
5. BILE SALTS
a. Hay’s Test: Principle
Bile salts present in the urine lower the surface tension of urine and so the sulphur powder
sinks to the bottom of the test tube.
6. BILE PIGMENTS:
a. Fouchet’s Test: Principle
Barium sulphate is formed as precipitate, which adsorbs bile pigments. Ferric chloride in
Fouchet’s reagent oxidizes Bilirubin to green color, biliverdin.
(Fouchet’s reagent - Ferric chloride in trichloro acetic acid).
REACTIONS OF ABNORMAL URINE
7. Dipstick Test : Dipstick (strip test) is based on change in color of indicators in presence of
glucose or protein. The commonly used indicators are tetrabromophenol for protein (Green)
and glucose oxidase-peroxidase (Red) for glucose.
