Sugar in urine sugar in urine background
In healthy individuals the glucose is filtered by the glomerulus and later almost completely reabsorbed in the proximal tubules. As the result, urine contains glucose only in minor amounts. When the glucose concentration in the blood exceeds the renal threshold level of 160-180 mg/dL (8.88-9.99 mmol/l,), namely, occurs hyperglycemia, the glucose reabsorption is ceased and glucose appears in the urine. Another mechanism which may lead to glucosuria is associated with the kidney diseases. In this case so-called renal glucosuria occurs and the concentration of glucose in the blood remains mormal.
However, glucosuria may occur sometimes in healthy individuals after having a meal with a high content of carbohydrates (glucose).
Normally, glucose is not present in the urine.
In 24-hour specimen the amount of glucose in the urine may reach 100 mg/24 hours (1-15 mg/dL).
Sugar in urine causes
- Diabetes mellitus;
- Cushing syndrome;
- Gestational diabetes;
- Pancreatic cancer;
- Cystic fibrosis;
- Central nervous system damage (asphyxia, tumors of hemorrhage);
- Severe burns;
- Advanced liver disease;
- Hyperglycemia may be induced by some drugs such as corticosteroids and ACTH, thiazides, oral contraceptives;
- Fanconi syndrome;
- Advanced renal disease;
- Pregnancy (should be distinguished from gestational diabetes);
Symptoms of hyperglycemia
Hyperglycemia is a condition characterized by the increased glucose concentration in the blood.
- Frequent voiding;
- Excessive thirst;
- Dryness of the mucous membranes;
- Skin dryness;
- Weight loss;
In the morning the bladder should be emptied and the second specimen should be collected for the test.
Benedict’s Qualitative Glucose Test
During the test 0.5 ml of urine is added to 5 ml of special reagent. After it is boiled for 5 minutes the color of the urine changes and the test results are being read.
- Green color – Negative, 0
- Yellow-green – + (< 0.5% glucose)
- Greenish yellow – ++ (0.5-1% glucose)
- Yellow – +++ (1-2% glucose)
- Orange to brick red – ++++ (over 2% glucose)
Paper test strips are also available. The strips contain glucose oxidase, peroxidase, chromogen (potassium iodide or tetramethylbenzidine), and buffer. The color intensity corresponds with the glucose concentration in urine.