M.Prasad NaiduMSc Medical Biochemistry, Ph.D,.

Colour:

Normal urine is amber coloured due to urochrome - Indoxyl—sulphate[ indican]

Yellow Bilirubin obstructive jaundice or due to vitamin

B complex tablets. On standing turns black in alkaptunuria due to oxidation of homogentisic acid .

Malignant melanoma – Black from the beginning melanuria

Red colour urine is seen in Hematuria Rifampicin(Anti tubercular drug )

Specific gravity normal is 1.015 to 1.025 Fixed specific gravity at 1010 in chronic

renal failure

Specific gravity decreased in Excessive water intake Chronic nephritis Steatorrhoea Diabetes insipidus

Specific gravity increased in

Diabetes mellitus

Nephrosis

Excessive perspiration

Specific gravity is tested by urinometer Volume: Normal around 1.5 liters / day Increased urinary volume in 1. excessive intake

of water Increased salt intake Diuretic therapy Diabetes mellitus Diabetes insipidus

Urine Volume decresed in excessive sweating Dehydration Low blood pressure & shock Oedema of any etiology Kidney damage Antidiuretic overactivity

Appearance Normal urine is perfectly clear and

transparent when freshly voided.May become turbid by phosphates or by pus

( Infection of the urinary tract ) or by chyle due to obstruction of lymphatics.

Odour: Normal urine is faintly aromatic due to

presence of volatile organic acids , when urine undergoes decomposition converted to ammonium carbonate giving unpleasant smell.

In Diabetic ketoacidosis urine is sweety smell due to acetone

Clinical Properties Reaction to litmus PH of urine is 5.5 to 7.5

A few hrs after meal alkaline as active secretion of Hcl from the stomach and make the blood more alkaline. So to counter act this kidney excretes more alkaline urine.

If the diet is rich in proteins more acidic urine is excreted. If more vegetable are taken urine will be alkaline as more acids are produced and these are converted to bicarbonate on keeping for some time pH may be changed due to bacterial activity.