How to Test for Diabetes

Studies show that diabetes can effect your entire body over time, but managing your blood sugar may help you prevent complications.^{[1]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source} Diabetes is a chronic health condition where your body either doesn't make enough insulin to control your blood sugar or doesn't properly use insulin anymore. Since it's so important to start treatment right away, you likely want to know for sure if you have diabetes. Experts agree that it's important to see your doctor as soon as you notice symptoms of diabetes so you can get tested.^{[2]XTrustworthy SourceCleveland ClinicEducational website from one of the world's leading hospitalsGo to source}

Part 1

Part 1 of 2:

Knowing When to Get Tested

1
Understand the main types of diabetes. Type 1 diabetes is characterized by the body's inability to produce insulin, a hormone that regulates the amount of sugar (glucose) in the blood and helps to transfer the glucose to your cells for energy. If your body isn't producing insulin, this means that the glucose stays in your blood and your blood sugar level can become too high. By contrast, type 2 diabetes is characterized by the body's inability to utilize and store glucose properly thanks to insulin resistance, which is usually connected to being overweight. In cases where there is excess weight, the muscle, liver and fat cells do not process insulin properly and the pancreas simply can't produce enough, causing blood glucose levels to increase.^{[3]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source}
- Type 1 diabetes (formerly known as juvenile diabetes) is usually diagnosed in children or teens, and can develop within just a few weeks. Meanwhile, type 2 develops over a period of time and with age, though it is becoming more and more common for children to experience early onset type 2 diabetes due to obesity.
- Approximately 10 percent of all diabetics are type 1 and require insulin to survive, whereas the overwhelming majority of diabetics are type 2 diabetics who suffer from an impaired glucose metabolism that leads to insulin deficiency.^{[4]XResearch sourceRutlege, J MD, Eiselein, L, et al The Challenge of Type I Diabetics are Type I. ILAR J. 2004;45(3):231-6.}
- There's also gestational diabetes, which occurs only during pregnancy. Because of the increase in hormone production during pregnancy, the amount of insulin is also increased to control glucose levels in the blood; however, if the body can't meet this demand for more insulin, then diabetes results. Gestational diabetes usually disappears after the birth, but can put the mother at a higher risk for type 2 diabetes later in life.^{[5]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source}
2
Be aware of the symptoms. Get tested if you exhibit the classic triad of diabetic symptoms: increased thirst (polydipsia), increased urinary frequency (polyuria), and increased hunger.^{[6]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source} You can assess whether you're experiencing an increase in these symptoms based on what is usually "normal" for you. For example, if you usually urinate seven or so times per day, but now urinate a lot more and have to get up in the middle of the night, something is not right and you should consult your primary care physician. Other symptoms include:
- A compromised immune system (e.g., wounds that don't heal quickly, persistent and recurring infections, such as a foot fungus or athlete's foot, yeast infections in the genitals or mouth, etc.)
- Tingling or pain in the hands or bottom of the feet (peripheral neuropathy)
- Lethargy and fatigue
- Blurred vision
- Increased appetite
- Unexplained weight loss
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3
Know the risk factors. Most of of the symptoms and risk factors for diabetes hold true for people age 45 and over; however, they're also being seen more often in obese people under age 40 and especially in obese teens. Major risk factors for developing diabetes include:^{[7]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source}
- A family history of diabetes
- High blood pressure (140/90 or higher)
- High level of triglycerides (250 mg/dL or higher)
- Low high-density lipoprotein, or HDL (good cholesterol) level (35 mg/dL or lower)
- Ethnicity (African-American, Hispanic, Native American or Pacific Islander)
- Obesity (a body mass index (BMI) higher than 25)
- A history of gestational diabetes
- Delivering a baby who weighed more than 9 lbs
- Diagnosis of Polycystic Ovarian Syndrome
- Existing cardiovascular disease
- The diagnosis of prediabetes
4
Know the screening guidelines. Healthy individuals without risk factors should get screened for diabetes at age 45 and then every three years thereafter. For those in high-risk groups, there is no clear-cut consensus on when screening should start, but the American Academy of Endocrinology has offered that a baseline screening should be sought for all those in the high-risk groups listed above.^{[8]XTrustworthy SourceNational Institute of Diabetes and Digestive and Kidney DiseasesHealth information from the National Institute of Diabetes and Digestive and Kidney Diseases, a division of the U.S. National Institutes of HealthGo to source}
- Note that those who belong to higher risk ethnic groups (African Americans, Hispanics, Native American, and Pacific Islanders) should get screened for diabetes at age 30, according to the American Academy of Endocrinology.
- If you have have been diagnosed with prediabetes, you should be checked for type 2 diabetes everyone one to two years.
- If you're younger than 45 but are overweight or obese, consider getting screened for prediabetes or diabetes.
- More than one-third of diabetics go for several years without a diagnosis, so it is best to follow these screening guidelines, as early diagnosis and treatment improves outcomes and decreases the likelihood of developing related health problems and conditions.^{[9]XResearch sourceMadonna M Roche, MSC, Peizhong Peter Wang MD PhD, Sex Differences in all cause mortality, Mortality from cardiovascular disease, hospitalizations for individuals patients with and without diabetes, and diabetics diagnosed early and late, Diabetes Care Sept 2013 Vol 36 No 9 2582-2590}
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Part 2

Part 2 of 2:

Getting Tested

1
Know that there are several methods to diagnose diabetes. These tests all involve testing your blood, although they do all not measure the same thing. Testing must be conducted in a certified and sanitary health care facility, such as a physician's office or medical laboratory. Each test usually needs to be repeated on a different day so that there are then two tests that can be used to reliably diagnose diabetes.^{[10]XTrustworthy SourceAmerican Diabetes AssociationHealth-based nonprofit focused on preventing and researching diabetesGo to source}
- There are three main tests used to diagnose whether someone has prediabetes (meaning you are at greater risk of developing diabetes) or diabetes: a glycated hemoglobin test, a fasting plasma glucose test, and an oral glucose tolerance test.^{[11]XTrustworthy SourceCleveland ClinicEducational website from one of the world's leading hospitalsGo to source}
- Note that if the blood glucose level of your blood is considered higher than normal according to one of the tests below and if you are showing classic symptoms of high blood glucose, your doctor may not require a second repeat test to make a correct diagnosis.
2
Get a glycated hemoglobin (A1C) test. This blood test provides information about your blood sugar levels over the past two to three months by measuring the percentage of blood sugar attached to the hemoglobin in the blood. Hemoglobin is a protein that carries oxygen in the red blood cells. The higher your blood sugar levels, the more sugar will be attached to the hemoglobin. A level of less than 5.7% is considered normal, while a level of 5.7% to 6.4% is considered to prediabetes, and 6.5% or higher is indicative of diabetes. This test is the standard test for diabetes assessment, management, and research.^{[12]XTrustworthy SourceCleveland ClinicEducational website from one of the world's leading hospitalsGo to source}
- You won't need to make a special appointment at a blood lab, but instead show up with your requisition form and get a standard blood sample drawn that is then sent to the laboratory for testing. In addition, this test is advantageous in that you don't have to fast or drink anything prior to testing. It can also be performed at any time of the day.
- Usually you will be tested twice, with each test occurring on a different day, to assess the average percentage of blood attached to your hemoglobin.
- The A1C test is not recommended if it is suspected that you have type 1 or gestational diabetes.^{[13]XTrustworthy SourceNational Institute of Diabetes and Digestive and Kidney DiseasesHealth information from the National Institute of Diabetes and Digestive and Kidney Diseases, a division of the U.S. National Institutes of HealthGo to source}
3
Undergo a fasting plasma glucose (FPG) test. This test assesses your fasting blood glucose levels. "Fasting" means that you refrain from eating or drinking anything but water, black coffee or unsweetened tea for eight hours prior to the blood test. Your doctor will look at a variety of factors from this blood test, including the glucose level, cholesterol and levels of enzymes in the liver and kidneys, as these organs are affected by diabetes. This test is the most common diagnostic tool for diabetes because it is more convenient and cost-effective than the oral glucose tolerance test.^{[14]XTrustworthy SourceMedlinePlusCollection of medical information sourced from the US National Library of MedicineGo to source}
- A normal reading is considered one of less than 100 mg/dl, while a reading of 100 to 125 indicates pre-diabetes. An FPG level of 126 is indicative of diabetes.^{[15]XTrustworthy SourceAmerican Diabetes AssociationHealth-based nonprofit focused on preventing and researching diabetesGo to source}
- Note that you will need to plan ahead for this test since you have to fast. For your own ease and comfort, this test is usually done first thing in the morning, before breakfast.
- Your doctor may want to repeat the same test on another day to confirm that the results are reliable.
- If your FPG level is very high, if you are showing symptoms of diabetes, or if you have been previously diagnosed as pre-diabetic, your doctor may want to move on to the next test in his arsenal, the oral glucose tolerance test to get a quick and firm diagnosis.
4
Have the oral glucose tolerance test (OGTT) test. This is a two-hour test that evaluates your blood glucose levels before and after you have a drink that is specially sweetened so your doctor can see how your body processes sugar. To prepare for this test, you'll need to make an appointment in advance for this test and fast eight hours before.^{[16]XTrustworthy SourceMedlinePlusCollection of medical information sourced from the US National Library of MedicineGo to source}
- At the beginning of your appointment, the doctor or nurse will test your blood glucose level (most likely with a simple finger-prick test, where your finger is pricked and the sugar in your blood is calculated via a digital monitor). You'll then drink a glucose beverage and sit for about two hours before someone tests your blood again.
- A level of 139 mg/dl or below is considered normal, while a reading of 140 to 199 indicates pre-diabetes, and 200 or higher indicates diabetes.
- Pregnant people undergo the OGTT to determine gestational diabetes; however, their glucose levels are tested four times with high (diabetic) levels being 95 or higher fasting, 180 or higher after one hour, 155 or higher after two hours, and 140 or higher after three hours.
5
Get a random plasma glucose test. Also called a Casual Plasma Glucose Test, this test is a blood check that occurs at any time of the day (meaning is not predicated on fasting the day before). This is usually reserved for individuals who have severe diabetes symptoms.^{[17]XTrustworthy SourceAmerican Diabetes AssociationHealth-based nonprofit focused on preventing and researching diabetesGo to source}
- In this test, diabetes is diagnosed when your blood glucose is 200 mg/dl or higher.^{[18]XTrustworthy SourceNational Institute of Diabetes and Digestive and Kidney DiseasesHealth information from the National Institute of Diabetes and Digestive and Kidney Diseases, a division of the U.S. National Institutes of HealthGo to source}
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Tips

If diagnosed as prediabetes, your doctor will suggest you make some changes in your daily life, such as increasing your exercise level, watching your diet, and losing a modest amount of weight; these steps can help you stave off full-blown diabetes.^{[19]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source}
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Note that "prediabetes" means that you have higher than normal blood glucose levels but that these levels are not quite high enough to be considered indicative of diabetes.^{[20]XTrustworthy SourceNational Institute of Diabetes and Digestive and Kidney DiseasesHealth information from the National Institute of Diabetes and Digestive and Kidney Diseases, a division of the U.S. National Institutes of HealthGo to source}
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Warnings

Around week 24 of their pregnancies, many people are tested for gestational diabetes when pregnant, which can severely impact a baby if left untreated. Fortunately, gestational diabetes can be managed by adhering to a strict diet.^{[21]XTrustworthy SourceCenters for Disease Control and PreventionMain public health institute for the US, run by the Dept. of Health and Human ServicesGo to source}
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Most people deemed prediabetic are more likely than those not labelled prediabetic to develop diabetes within 10 years and are more likely to suffer from a serious heart problem, such as a heart attack or stroke.
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