Diabetes is a disease that occurs when your blood glucose, also called blood sugar, is too high. Blood glucose is your main source of energy and comes from the food you eat. Insulin, a hormone made by the pancreas, helps glucose from food get into your cells to be used for energy. Sometimes your body doesn’t make enough—or any—insulin or doesn’t use insulin well. Glucose then stays in your blood and doesn’t reach your cells.

Over time, having too much glucose in your blood can cause health problems. Although diabetes has no cure, you can take steps to manage your diabetes and stay healthy.

Sometimes people call diabetes “a touch of sugar” or “borderline diabetes.” These terms suggest that someone doesn’t really have diabetes or has a less serious case, but every case of diabetes is serious.

https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes

Diagnosis

There are several ways to diagnose diabetes. Each way usually needs to be repeated on a second day to diagnose diabetes.

Testing should be carried out in a health care setting (such as your doctor’s office or a lab). If your doctor determines that your blood sugar level is very high, or if you have classic symptoms of high blood sugar in addition to one positive test, your doctor may not require a second test to diagnose diabetes.

A1C

The A1C test measures your average blood sugar for the past two to three months. The advantages of being diagnosed this way are that you don't have to fast or drink anything.

• Diabetes is diagnosed at an A1C of greater than or equal to 6.5%
   

Result

A1C

Normal

less than 5.7%

Prediabetes

5.7% to 6.4%

Diabetes

6.5% or higher

Fasting Plasma Glucose (FPG)

This test checks your fasting blood sugar levels. Fasting means after not having anything to eat or drink (except water) for at least 8 hours before the test. This test is usually done first thing in the morning, before breakfast.

• Diabetes is diagnosed at fasting blood sugar of greater than or equal to 126 mg/dl
   

Result

Fasting Plasma Glucose (FPG)

Normal

less than 100 mg/dl

Prediabetes

100 mg/dl to 125 mg/dl

Diabetes

126 mg/dl or higher

Oral Glucose Tolerance Test (OGTT)

The OGTT is a two-hour test that checks your blood sugar levels before and two hours after you drink a special sweet drink. It tells the doctor how your body processes sugar.

• Diabetes is diagnosed at 2 hour blood sugar of greater than or equal to 200 mg/dl
   

Result

 Oral Glucose Tolerance Test (OGTT)

Normal

 less than 140 mg/dl

Prediabetes

 140 mg/dl to 199 mg/dl

Diabetes

 200 mg/dl or higher

Random (also called Casual) Plasma Glucose Test

This test is a blood check at any time of the day when you have severe diabetes symptoms.

• Diabetes is diagnosed at blood sugar of greater than or equal to 200 mg/dl

What is prediabetes?

Before people develop type 2 diabetes, they almost always have "prediabetes"—blood sugar levels that are higher than normal but not yet high enough to be diagnosed as diabetes.

Doctors sometimes refer to prediabetes as impaired glucose tolerance (IGT) or impaired fasting glucose (IFG), depending on what test was used when it was detected. This condition puts you at a higher risk for developing type 2 diabetes and cardiovascular disease.

https://www.diabetes.org/a1c/diagnosis

Treatment

Depending on what type of diabetes you have, blood sugar monitoring, insulin and oral medications may play a role in your treatment. Eating a healthy diet, maintaining a healthy weight and participating in regular activity also are important factors in managing diabetes.

Treatments for all types of diabetes

An important part of managing diabetes — as well as your overall health — is maintaining a healthy weight through a healthy diet and exercise plan:

• Healthy eating. Contrary to popular perception, there's no specific diabetes diet. You'll need to center your diet on more fruits, vegetables, lean proteins and whole grains — foods that are high in nutrition and fiber and low in fat and calories — and cut down on saturated fats, refined carbohydrates and sweets. In fact, it's the best eating plan for the entire family. Sugary foods are OK once in a while, as long as they're counted as part of your meal plan.

Yet, understanding what and how much to eat can be a challenge. A registered dietitian can help you create a meal plan that fits your health goals, food preferences and lifestyle. This will likely include carbohydrate counting, especially if you have type 1 diabetes or use insulin as part of your treatment.

• Physical activity. Everyone needs regular aerobic exercise, and people who have diabetes are no exception. Exercise lowers your blood sugar level by moving sugar into your cells, where it's used for energy. Exercise also increases your sensitivity to insulin, which means your body needs less insulin to transport sugar to your cells.

Get your doctor's OK to exercise. Then choose activities you enjoy, such as walking, swimming or biking. What's most important is making physical activity part of your daily routine.

Aim for at least 30 minutes or more of aerobic exercise most days of the week, or at least 150 minutes of moderate physical activity a week. Bouts of activity can be as brief as 10 minutes, three times a day. If you haven't been active for a while, start slowly and build up gradually. It's also a good idea to avoid sitting for too long — aim to get up and move if you've been sitting for more than 30 minutes.

https://www.mayoclinic.org/diseases-conditions/diabetes/diagnosis-treatment/drc-20371451