1. Know the Symptoms
Symptoms of glucose intolerance (also called "pre-diabetes") closely mirror those of diabetes itself. For example, excessive thirst and needing to urinate more than usual are also problems of diabetes. In addition, increased appetite, even after having a meal, has been reported in those with glucose intolerance. An important symptom to spot is blurry vision, as this is one of the final symptoms to appear prior to the onset of full-blown diabetes. If you are suffering from other symptoms such itchy skin or numbness in your extremities, you should see a doctor immediately, as you may have fully developed the disease.
2. Take an Oral Glucose Tolerance Test
An oral glucose tolerance test can spot pre-diabetes as well as diabetes mellitus and gestational diabetes. For this test you are typically required to fast overnight or at least eight hours, but not more than 16 hours. The doctor takes a blood sample to serve as a baseline, then takes additional measurements as you are given small amounts of glucose over the next three hours. Any fasting readings below 126 mg/dl indicate glucose intolerance, and any readings taken later in the test that fall between 140 and 199 mg/dl are also indicative of the condition. The major drawback of the oral glucose tolerance test is that the readings can be ineffective if the patient has any pre-existing conditions, even one as minor as a head cold.
3. Fasting Plasma Glucose Testing
Like the oral glucose test, the fasting plasma glucose test measures the level of glucose in your bloodstream. You're again required to fast for at least eight hours prior to testing. Once you've done so, the doctor will take a blood sample and submit it for analysis. If the results show a blood glucose level between 70 and 100 mg/dl, you are considered to have normal blood glucose levels. If your blood glucose levels fall between 101 and 126 mg/dl, however, this may indicate pre-diabetes.
