Glucose Levels in Urine

The presence of glucose in the urine is called glycosuria. In normal situations, there exists no glucose in the urine. The kidneys ensure that the entire glucose content, is filtered back and sent into the bloodstream.

When the glucose levels in the blood rise and is left untreated, such as during conditions of diabetes mellitus, presence of glucose in urine is seen. Diabetes mellitus is not the only condition due to which glucose is found in urine.

Renal glycosuria and excessive consumption of carbohydrates also conduces to presence of glucose in urine. Moreover, renal glycosuria during pregnancy also results in abnormally high glucose levels in urine during pregnancy.

Most of the dietary carbohydrates are converted to glucose in the body. This glucose in the blood is used to provide energy for various functions in the body. Insulin is the hormone that regulates the level of glucose present in the blood. During times of high blood glucose levels, the pancreas secrete insulin and bring down the level of glucose in the blood. Mostly, in the mornings, blood sugar levels are low and elevate after every meal.

There are two glucose readings taken: fasting and post meal. For the fasting reading one should fast for 8 to 10 hours before taking the glucose test and the next reading is taken 2 to 3 hours later after a meal has been eaten. Some may even be asked to consume glucose solution and take the test after an hour.

Fasting glucose levels between 70 and 126 mg/dl is said to be normal. Moreover, for post meal a reading between 140 and 180 mg/dl is considered normal.

Anything higher is termed as hyperglycemia and the person is called diabetic. Lower than the mentioned levels of blood glucose is termed as hypoglycemia. However, this was all about blood glucose levels in blood.

In urine, there should not be any signs of glucose. Even if there exists urine, it will be in the small range of 0-15 mg/dl. There is no such thing as normal glucose levels in urine, because glucose is not supposed to be present in urine, in the first place.

Glucose will seep into the urine only when there is excess glucose in the blood and the kidney is too overwhelmed to reabsorb all that excess amount of glucose. This point is known as the renal threshold of glucose (RTG). There is another case as well. If this RTG is low, even normal blood sugar levels result in seeping of glucose into the urine.

Glucose in urine above the small range mentioned can be due to different conditions like renal glycosuria, diabetes mellitus, gestational diabetes and excessive consumption of carbohydrates.

The level of glucose in urine is determined by the "spot test", which will tell us if glucose is present in urine or not. This test involves a dipstick and a color-sensitive pad, which is saturated with specific chemicals reacting with glucose. When the urine is brought in contact with the color-sensitive pad, along with the dipstick, the pad will change colors, if there exists glucose in the urine. Moreover, the shade and color will also indicate the concentration of glucose in urine.

There also exist test strips, which when dipped into the urine sample, will change color in presence of glucose, at the indicated time and will indicate its concentration. One can crosscheck with the reference color chart in the kit to understand what the different colors stand for.

When the test reveals abnormal glucose levels in urine, further investigation is done. However, for people with low RTG (renal glycosuria), interpreting urine tests is difficult. People on medication need to inform the health care provider about the same.

People with diabetes carry out these tests on a regular basis. They jot down the different test observations and take them along, during the next visit to the doctor's clinic. These tests are especially beneficial to people who hate pricking themselves for testing glucose levels from blood.

The greatest drawback about these urine tests for blood glucose in urine is that they do not indicate low glucose levels in urine, but only give the signal when the glucose levels in urine are high, above 10 mmol/L. Moreover, certain medications can also interfere with test results.

During pregnancy, some women are found to have glucose in their urine. This usually develops after the 20th week of pregnancy and is known as gestational diabetes. About one-sixth of pregnant women are seen to have glucose in their urine. This happens due to the changes in the kidney's filtration system during pregnancy.

Carrying out a glucose urine test to check glucose levels in urine, is a very easy and inexpensive procedure. Test kits are easily available, which can be used to test high glucose levels within the four walls of the house itself!