Diabetes is a long-term (chronic) condition that happens when your body doesn’t produce enough insulin, or can’t use insulin well. As a result, your blood sugar can become too high, leading to serious health problems.
To make a type 2 diabetes diagnosis, doctors can use several different blood tests. You’ll typically need to be tested at least twice to confirm a diagnosis. Most people are tested for diabetes because of age or other risk factors.
Types of Diabetes
The three main types of diabetes are gestational diabetes, type 1 diabetes, and type 2 diabetes.
Gestational diabetes
Gestational diabetes happens when you develop high blood sugar during pregnancy. It’s important to manage gestational diabetes well to reduce the risk of complications for you or your baby.
Gestational diabetes usually goes away after the baby is born. But having gestational diabetes increases your risk of developing type 2 diabetes. After pregnancy, your doctor will test your blood sugar level to make sure you no longer have diabetes.
Type 1 diabetes
People with type 1 diabetes don’t produce insulin in their bodies. As a result, they need to take insulin every day. Type 1 makes up 5 to 10 percent of all cases of diabetes, according to the Centers for Disease Control and Prevention (CDC). It’s usually diagnosed by early adulthood.
Type 2 diabetes
Type 2 diabetes has a different cause than type 1 diabetes. Unlike those with type 1, people with type 2 diabetes can produce insulin, but their bodies don’t use it very well.
This type makes up 90 to 95 percent of all diagnosed cases of diabetes. It’s sometimes called adult-onset diabetes. Although it can occur at any age, type 2 diabetes is more common in people older than 45.
If you think you might have diabetes, talk to your doctor. Uncontrolled type 2 diabetes can cause severe complications, such as:
- amputation of the feet or legs
- vision problems or blindness
- heart disease
- kidney disease
- stroke
Type 2 diabetes is also associated with high cholesterol. It can cause your LDL or “bad” cholesterol and triglycerides to go up, and your HDL or “good” cholesterol to go down. These changes can increase your risk of cardiovascular disease.
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Symptoms of type 2 diabetes
Some people are diagnosed with type 2 diabetes because they have noticeable diabetes symptoms. Early symptoms can include:
- increased or frequent urination
- increased thirst
- fatigue
- blurry vision
Skin conditions
There are also several skin conditions that can sometimes be a sign of diabetes. These include:
- cuts and sores that won’t heal. The effects of high blood sugar can reduce your skin’s ability to heal. This can lead to infections and skin ulcers.
- darker, thicker, velvety skin in places where your skin folds. Acanthosis nigricans is a skin pigment condition found in areas like your armpits, neck, hands, knees, groin, and inside elbows.
- skin tags. These tiny skin growths usually happen on your eyelids, armpits, neck, and groin.
- raised bumps that turn into patches of solid, hard skin. Necrobiosis lipoidica can cause yellow, brown, or reddish patches to form on your skin.
- unusually thick, hard skin on your fingers, toes, or both. Digital sclerosis can make it difficult to move your fingers.
- a rash of small, itchy, painful, pimple-like bumps that turn yellow. Eruptive xanthomatosis can happen when a person has high triglycerides. Often, people diagnosed with eruptive xanthomatosis have diabetes. But this condition also happens in people who do not have diabetes.
- shin spots. Diabetic dermopathy causes visible spots or lines that create a small dent in the skin.
Keep in mind that these symptoms, on their own, do not always indicate diabetes. But if you notice these changes, it’s a good idea to get them checked out by a doctor.
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How doctors diagnose type 2 diabetes
The symptoms of type 2 diabetes often develop gradually. Because you may or may not have symptoms, your doctor will use blood tests to confirm your diagnosis.
These blood tests can be used to measure the amount of sugar (glucose) in your blood:
- A1C (glycated hemoglobin) test
- fasting plasma glucose test
- random plasma glucose test
- oral glucose tolerance test
- We’ll look at each of these tests in more detail later in the article.
Your doctor will request one or more blood tests to confirm your diagnosis. A test will usually be completed more than once to confirm the result unless you have clear symptoms of diabetes.
What to expect during blood sugar testing
To do a blood test, a lab technician, nurse, or other healthcare professional will use a small needle to draw a sample of your blood. The sample is then sent to a lab for testing.
Some diabetes tests require you to prepare for the test. For example, you may be asked to fast (avoid eating and drinking) for a set period of time before the test. Your doctor will give you instructions to tell you how to prepare for your tests.
Your blood sugar test results can be affected by other health conditions or medications, so tell your doctor about any illness or stress you’re experiencing. And make sure your doctor knows about the medications you’re taking.
Who should be tested for type 2 diabetes?
Most often, people are diagnosed with type 2 diabetes through routine screening tests. Routine screening means that you are tested because you may be at risk of having diabetes, even when you don’t have any signs or symptoms.
Routine screening for diabetes typically starts at age 45. You should be screened sooner if you have the following:
- high blood pressure
- cardiovascular disease
- obesity or are overweight
- polycystic ovary syndrome
- acanthosis Americans, a skin condition
- a family history of type 2 diabetes
- a history of gestational diabetes or you’ve given birth to a baby weighing over 9 pounds (4.1 kilograms)
- Black, Latino/Hispanic, Asian, Native American, Alaska Native, or Pacific Islander descent
- a low level of HDL (“good”) cholesterol or a high triglyceride level
- a sedentary lifestyle
Routine screening uses blood tests to check for signs of diabetes.