9 Best Medical Tests for Diabetes [2023]

Diabetes is like a snowball effect, where small complications can build up over time, causing health problems. That's why you should monitor your blood sugar levels.

There are lots of tests for diabetes that can gauge how well your blood sugar is under control. Some can be done at home, while others must be done at a doctor's clinic or a lab.

In this article, we'll cover the best nine medical tests for diabetes, how to interpret them, their purpose, and everything else you need to know to stay healthy!

Diabetes is a health condition characterized by high blood sugar levels, known as hyperglycemia. 

This is usually due to insufficient insulin production or the body's inability to use insulin properly (insulin resistance).

There are several types of diabetes, but the main ones are type 1 and type 2 diabetes.

• Type 1 Diabetes: Also called insulin-dependent diabetes, type 1 is caused by an autoimmune disorder where your body mistakenly attacks the pancreas's insulin-producing cells. People with type 1 diabetes produce little to no insulin and end up taking insulin for life.

• Type 2 Diabetes: The most common type of diabetes where your body produces insulin, but it's either not enough or ineffective due to insulin resistance.

• Gestational Diabetes: A temporary type of diabetes that happens during pregnancy due to hormonal and metabolic changes. It's when healthy pregnant mothers develop transient high blood sugar.

• Prediabetes: An intermediate condition between normal blood sugar and diabetes, where blood sugar is high but not diabetes-level high.

Lots of people have prediabetes and don't know it. They're liable to develop full-blown diabetes if they don't regularly monitor and test their blood sugar.

Keeping track of your blood sugar level is even more critical if you have diabetes. It helps you manage your condition and avoid complications, the worst of which is death.

Keeping your blood sugar levels in an optimal range can help you avoid cardiovascular disease, kidney diseases, nerve damage, eye problems, and foot infections that can lead to amputations. 

Luckily, there are several diabetes tests you can take to keep a hold of things.

If you have any of these risk factors or experience these symptoms, you should monitor your blood sugar more frequently and follow up with your health care provider.

Diabetes Symptoms:

• Feeling thirsty more often than usual

• Needing to urinate frequently

• Feeling hungry more often

• Always tired

• Blurry vision or eye problems

• Unexplained weight loss

• Slow-healing sores or wounds

• Experiencing numbness or tingling in the feet

Risk Factors:

• Age 35+ (The American Diabetes Association recommends annual diabetes screening for ages 35 and older)

• Prediabetes or previous gestational diabetes

• Obesity or excessive weight

• Family history of diabetes

• High blood pressure or heart disease

Here are the best diabetes tests for monitoring your blood sugar levels and your overall health. Some can give you an indication of whether or not you have diabetes, while others can help gauge the impact of diabetes on your health.

A fasting blood sugar test, also called fasting plasma glucose (FPG), measures your blood glucose levels after fasting for at least eight hours. It can greatly indicate whether you're healthy or have prediabetes or diabetes.

Ideally, you want to do the test first thing in the morning for the most reliable results. You can do it yourself at home or in a lab.

There are three possible outcomes according to your fasting blood glucose levels:

• 99 mg/dL or below: Normal range

• 100 to 125 mg/dL: You likely have a form of prediabetes called impaired fasting glucose (IFG)

• 126 mg/dL or more: Likely have diabetes, but you should repeat the test on a different day to make sure

People with impaired fasting glucose are liable to develop diabetes if they don't monitor their blood glucose levels and adjust their lifestyles. They're also at higher risk of complications like heart disease.

Minor lifestyle changes like following a healthy diet, regular exercise, and weight management can help prevent or delay the onset of diabetes in people with IFG.

Another blood test for diagnosing diabetes is the oral glucose tolerance test (OGTT). It's similar to the fasting blood sugar test since both require that you fast for at least eight hours, but studies have shown that the OGTT is more sensitive.

The OGTT is done in a lab where your blood sugar level is tested before and two hours after swallowing a glucose solution containing 75 grams of glucose.

The idea is to see how your body treats the sugar you ingest and how much your plasma glucose spikes. Here are the possible test results you can see two hours after the test:

• 139 mg/dL or more: Normal range

• 140 to 199 mg/dL: You likely have a kind of prediabetes called impaired glucose tolerance (IGT)

• 200 mg/dL or more: Likely have diabetes, but you should repeat the test on a different day to make sure

OGTT FOR GESTATIONAL DIABETES

The OGTT can also help identify gestational diabetes in most pregnant women. You'll likely be tested around the 24th to 28th week of pregnancy.

During an OGTT, you'll be required to drink a solution of 100 grams of glucose. Then, your blood glucose levels are measured four times over three hours. Based on your blood sugar level, you're likely to have gestational diabetes if your results are as follows:

• Fasting: 95 mg/dL or higher

• After one hour: 180 mg/dL or higher

• After two hours: 155 mg/dL or higher

• After three hours: 140 mg/dL or higher

The A1c test (also known as HbA1c and glycated hemoglobin test) measures your average blood sugar level over the last three months.

It's typically done in a lab where a technician takes your blood sample and measures how much of your red blood cells are coated with sugar molecules. This gives an indication of how well your blood sugar is under control and can be used to diagnose diabetes.

There are three possible results for an A1c test:

• Below 5.7%: Normal range

• 5.7 to 6.4%: Prediabetes

• 6.5% or more: Diabetes

If your A1c is 6.5% or above, your doctor will likely put you on a combination of diet, exercise, and medication to help control your blood sugar.

It's recommended to do the A1c test every three months, especially for people with diabetes and prediabetes.

A random blood sugar test measures your glucose levels at any time of day without fasting. It's the easiest and most common test you can do at home, at a doctor's clinic, or in a lab.

A random blood sugar level of 200 mg/dL or more can indicate diabetes. However, a random blood sugar test isn't very accurate, and if you suspect you have diabetes, it's better to follow up with an A1c or fasting plasma glucose test.

The glucose challenge test (GCT), also called the glucose screening test, is another test done to identify gestational diabetes in pregnant women.

It's similar to the oral glucose tolerance test, but with the GCT, you don't need to fast beforehand. You're given a solution containing 50 grams of glucose dissolved in water, and your blood sugar level is measured after one hour.

If your blood sugar level is 135 mg/dL to 140 mg/dL or higher, there's a good chance you might have gestational diabetes. Your doctor will likely ask you to do an oral glucose tolerance test to confirm.

All of the blood tests mentioned so far only tell you if you have diabetes or not. None of them tell you the type of diabetes you might have. You might have type 1, type 2, gestational, or even monogenic diabetes, a rare type of diabetes caused by a genetic mutation.

After doing a blood test, genetic testing can help you determine the type of diabetes you have. This is especially useful in the case of monogenic diabetes, which can only be detected through genetic testing.

Genetic testing is sometimes recommended for people with a family history of diabetes, although it's uncommon.

If you have diabetes and a family history of type 1 diabetes, your healthcare provider might ask you to do a few extra blood tests. One of them is autoantibodies testing, which is done to determine whether or not you have type 1 diabetes.

Autoantibodies are antibodies that mistakenly attack the beta cells of your pancreas, which are responsible for producing insulin. If these autoantibodies are found in your blood sample, you most likely have type 1 diabetes.

A glucose in urine test measures the amount of sugar in your urine. It's not a typical diabetes test since it doesn't confirm or diagnose diabetes, but it can indicate if something is wrong with your blood sugar and kidneys.

The normal range for a urine glucose test is 0 to 15 mg/dL. Any higher than that signals that you might have too much glucose in your urine, which warrants a diabetes investigation.

It could also be due to pregnancy, gestational diabetes, or certain kidney diseases.

Diabetes is a condition that can affect almost every cell in your body. Elevated blood sugar levels can damage the nerves and blood vessels going to different organs, leading to complications.

This is why individuals with diabetes need to monitor vital functions and perform other medical tests that aren't specifically for diabetes. Some of the most important medical tests include:

Regularly check your feet for cuts, sores, scrapes, and wounds you might not feel due to the damaged nerve endings. If left untreated, they can cause infections and complications, possibly leading to lower limb amputation.

Two in three people with diabetes develop hypertension or high blood pressure. Monitor your blood pressure to avoid heart disease, stroke, and other complications. The ADA recommends a target blood pressure of less than 130/80 mmHg.

Diabetes is the primary cause of kidney disease. If you have this health condition, you should perform kidney function tests such as urine albumin and creatinine tests at least once a year to be safe.

Ideally, you want your creatinine levels to be less than 1.2 for women and less than 1.4 for men.

People with diabetes are more likely to develop high levels of triglycerides and LDL cholesterol and should monitor their lipid profiles. Ideally, you want your LDL to be lower than 70 mg/dL and your triglycerides below 150 mg/dL.

Elevated blood sugar levels can lead to dental infections and other mouth-related problems. This is because microbes and bacteria grow in sugar-rich conditions, which can lead to cavities and gum disease.

If you experience bleeding or swollen gums, you should check with your dentist about the possibility of gum disease.

Diabetes increases your chances of blindness, blurred vision, glaucoma, and other eye problems. You should visit your ophthalmologist at least once a year for a dilated eye exam to make sure you don't have diabetic retinopathy.

Life is sweeter when you keep your glucose in check.

Monitoring and testing your blood glucose regularly is crucial, whether you have diabetes or are perfectly healthy. It can help you avoid an assortment of health problems and significantly improve the quality of your life.

Treat these nine medical tests for diabetes like your safety net. If your blood sugar levels ever spiral out of control, they'll catch you before complications can develop.