Diabetes Symptoms - Tests & Diagnosis
If you are at risk for diabetes because of your weight and age or are experiencing symptoms that suggest you might have diabetes, including increased thirst, increased hunger, frequent urination, unexplained weight loss, or a tingling sensation in the hands or feet, your doctor will prescribe a blood glucose test to confirm the diagnosis. If you are diagnosed with diabetes, it is important to take care of your blood glucose levels or it can cause other health problems.
Fasting Plasma Glucose Test
The most common and preferred test for diagnosing diabetes is the fasting plasma glucose test (FPG). It can also be used to test for pre-diabetes. To prepare for the test, you must not eat anything for at least eight hours before taking the FPG test. The test is usually scheduled for first thing in the morning so that you can take the test following an overnight fast. During the test, blood will be drawn which will be sent to the lab for analysis.
The FBG test will measure the level of glucose in your blood after fasting. People who do not have diabetes have a normal fasting blood glucose level between 70 and 100 mg/dl (milligrams per deciliter). A fasting blood glucose level between 100 and 125 mg/dl indicates pre-diabetes. A person is diagnosed with diabetes if his/her fasting blood glucose level is 126/mg/dl or greater on two separate blood tests.
If your fasting blood glucose tested in the normal range, but you have symptoms of diabetes or have factors which put you at risk for diabetes, your doctor may have you take another test known as the oral glucose tolerance test to verify the results. This is because some people have a normal fasting blood glucose level, but reach a high blood glucose level quickly when they eat. This may signal a glucose intolerance and if the level of blood glucose is high enough it may indicate diabetes.
Oral Glucose Tolerance Test
The oral glucose tolerance test (OGTT) is another method used to diagnose diabetes. This test is usually only performed during pregnancy to check for gestational diabetes or to test someone with the symptoms of diabetes who had a normal fasting glucose level. It is sometimes used to test for pre-diabetes as well.
With the OGT test, a persons blood is drawn twice for analysis. The first measurement requires an overnight fast of at least eight hours. After the first blood sample is obtained, the person is given a glucose-rich drink. Two hours later, the blood will be drawn a second time. At the two hour measurement, a normal blood glucose level is below 140 mg/dl, a pre-diabetes level is 140 to 199 mg/dl, and a diabetes level is if the blood glucose rises to 200 mg/dl or more.
Casual Plasma Glucose Test
Another method used to check for diabetes is the casual plasma glucose test. With this test, a fast is not required and blood is drawn without any consideration as to when food was last eaten. A blood glucose level of 200 mg/dl or more may indicate diabetes. The test may be repeated to verify the diagnosis.
Testing for Diabetic Kidney Disease
One of the harmful results of diabetes is kidney disease, which affects about twenty to forty percent of diabetics. The kidney damage occurs when the main protein in the blood called microalbuminuria leaks into the urine. If the leakage is not stopped, the damage to the kidneys will continue until they eventually stop working. It is important to test the urine for protein on a regular basis, so that appropriate treatment can be given.
The urine test is first given when a person is initially diagnosed with type 2 diabetes. This is to screen for any kidney disease that may have already occurred, since type 2 diabetes is usually present for some time before a diagnosis is made. A person with type 1 diabetes usually takes a urine test for the first time five years after diagnosis. The urine test is then usually performed on an annual basis.
If the test results are positive for kidney damage it means that there is damage to the blood vessels in the kidneys as well as to blood vessels thru out your body, increasing your risk of heart problems. Your doctor will take steps to try and slow the progression of any further damage. Treatment usually involves medication, more aggressive treatment for your diabetes, better control of blood sugar levels, and getting your blood pressure and cholesterol to healthy levels.
The Glycated Hemoglobin Test
The glycated hemoglobin test (HbA1c) is an important blood test for diabetics. It is used along with home blood glucose monitoring to determine if a person has ones diabetes under control and if adjustments need to be made in ones treatment or diabetes medications. The HbA1c test can determine how much sugar was in the blood for the previous six to twelve weeks by measuring the amount of glycated hemoglobin. Glycated hemoglobin forms when blood glucose levels are too high, causing sugar to build up in the blood and combine with hemoglobin. (Hemoglobin is the part of the red blood cells that moves oxygen thru out the body). Elevated HbA1c measurements increase the risk of diabetes related health problems. It is usually recommended that the test be taken every three months, although some diabetics have their blood sugar levels under good control and may wait longer between tests. At a minimum, diabetics should take the test every six months to make sure their diabetes and blood sugar levels are under control.