Sugar in Urine, Treatment, Procedure, And Symptoms

 Sugar in Urine

Determination Of Glucose

Clinical Significance

A small amount of glucose 2-20 mg/dl may be present in fasting urine which is not detectable by chemical methods. The presence of the chemically detectable amount of glucose in the urine is called glycosuria or glucosuria.

The quantity of glucose that appears in the urine is dependent upon:

  • Blood sugar level
  • The rate of glomerular filtration
  • The degree of tubular reabsorption.

1. The normal renal threshold for glucose is 150-170 mg/dl. When the glucose exceeds the renal threshold the tubules cannot reabsorb all of the filtered glucose and then glycosuria occurs. The main reason for glycosuria is hyperglycemia. Elevated blood sugar level. Diabetes mellitus the most common cause of hyperglycemia.

2. Glucose is also found in the urine of some hyperglycemia patients with endocrine hyperactivity that is in:

  1. Hyperthyroidism
  2. Hyperpituitarism
  3. Hyperadrenalism

Injection of the hormones of these glands can also produce glycosuria, the other conditions which may cause glycosuria due to hyperglycemia are myocardial infarction, cerebral hemorrhage, brain tumors, severe liver disease, and whole organ disease of the pancreas.

3. In renal glycosuria, due to the defect in the reabsorption ability of the renal tubule and due to the subsequent lowered renal threshold, glucose appears in urine following ingestion of food. The blood sugar level is, however normal. There are other types of tubular defects that result in the decreased ability to reabsorb glucose. These can include cystinosis and heavy metal poisoning and Fanconi syndrome. Depression of renal function to 30% of the normal or less, results in symptomatic renal glycosuria which has also been observed in acute renal failure.

4. There are various other nonpathological cases of transitory hyperglycaemia which will result in glycosuria. These conditions are as follows:

  • Pregnancy: Gycosuria is due to lowered renal threshold. Lactose may be present in urine.
  • Stress and anxiety: Hyperglycaemia due to an increased output of epinephrine and glucocorticoid.
  • Alimentary glycosuria may occur due to intake of a large number of carbohydrates at one time following the intake of low carbohydrate diet for about a week. During this period the body’s tolerance for glucose is decreased and sugar will pass from the intestinal tract into the bloodstream faster then the liver can remove it.

Note: In the case of transitory hyperglycaemia blood sugar level returns to normal once the person is out of that pacific condition, which causes hyperglycaemia.

Name of the Test

Benedict’s qualitative test

Principle of the Test

When Benedict’s qualitative reagent (5 ml) is heated with eight drops of urine (about 0:5 ml), glucose present in urine reduces cupric ions present in the reagent to cuprous ions. Alkaline medium is provided to the reaction by sodium carbonate present in the reagent. The original colour of Benedict’s reagent is blue. It changes to green, yellow, orange or red, according to the. the concentration of glucose present in urine.

Note The test is non-specific for glucose since the reaction may be brought by other carbohydrates. Such as fructose galactose, lactose and pentose and also by no carbohydrates such as ascorbic acid, salicylates, creatine and uric acid. Hence if Benedict’s test is positive it is necessary to perform glucose oxidase (heuristic) test to confirm whether it is due to only glucose.


Benedicts qualitative reagent


Sodium Citrate = 173gm.
Sodium carbonate = 100 gm.
Place in about 900 ml of distilled water. Boil for 2-3 mins. Cool and add cupric sulphate = 1.73 gm.

Dissolve and make a final volume of 1 litre. store in a polyethene container.

Sugar In Urine Treatment Procedure 

1. Pipette 5.0 ml of Benedict’s reagent in a test tube (20x 150 mm)

2. By using Pasteur pipette, add eight drops the urine.

3. Heat carefully on the flame of a gas burner or spirit lamp or place on boiling water for 5 to 10 minutes.

4. Cool under tap water or by placing ina beaker containing tap water.


  1. Blue – Sugar- Absent
  2. Green And Slight Yellow – Sugar- Present
  3. Green And Thick Yellow – Sugar Present,+ to ++
  4. Yellow. And Orange – Sugar, Present, +++
  5. Orange and Red – Sugar, ++++

Note: If Benedict’s test is positive then it is necessary to confirm it by using glucose-oxidase Uri-stix. If glucose is present then use above mention tabular observations to grade the results. If glucose is absent then it may be necessary to identify the reducing substance present in urine.
Spread the love

Leave a Comment