Medically Reviewed By: Tom Iarocci, MD

You may not spend a great deal of time thinking about your blood sugar levels — unless, of course, you are one of the many people who suffer from diabetes. Blood sugar readings, or glucose levels, are consistently higher than normal when you have diabetes. Without adequate control of these levels, over time, this can lead to many different health conditions and even damage to your vital organs.

Unfortunately, the human body does not come with a dashboard, and with prediabetes and type 2 diabetes, there is usually nothing that would be equivalent to a warning light, telling you that your blood sugar has started going too high. Since there may be no symptoms at first, some people have a hard time accepting that uncontrolled blood sugar could be devastating to their health, even after they find out about their condition from blood tests. However, understanding your blood glucose levels and knowing which values are in a good range and which are not is essential in managing your diabetes and warding off complications.

What Are Normal Blood Sugar Levels?

Normal depends on whether or not you have diabetes. Normal also depends on how long it’s been since you have had food or beverages other than water. In people who do not have diabetes, the American Diabetes Association considers anything between 70 and 100mg/dL to be a normal reading after a period of fasting—that is, going without food or caloric intake for at least 8 hours, such as after sleeping. In people without diabetes, it is normal to have levels at 140 mg/dL or lower two hours after eating a meal.

During the day, blood sugar levels will be at their lowest just before it's time for a meal. The concept of low blood sugar is a tricky one because this varies widely from one person to the next. Values below 70 mg/dL are generally considered low. In healthy people, glucagon is a hormone that stimulates the liver to release stored glucose into your bloodstream when blood sugar levels fall too low.

Do You Have Diabetes?

Doctors use various tests in determining whether you have diabetes – from the fasting plasma glucose test, to the oral glucose tolerance test. Sometimes the diagnosis of diabetes is made by a random blood test that shows blood sugar elevated beyond doubt, higher than 200. Higher levels of glucose in the blood may be accompanied by various symptoms, such as constant thirst, or the need to go to the bathroom more often. However, any levels of blood sugar that are higher than normal are unhealthy, whether they produce symptoms or not, and if your glucose is high without reaching the point of diabetes, you may be diagnosed with prediabetes.

According to the American Diabetes Association, more than 86 million people across the United States suffer from prediabetes, and most of them do not know it. Without taking steps such as weight loss and increasing physical activity levels, about 15 percent to 30 percent of people with prediabetes will develop type 2 diabetes within five years.

Managing Diabetes:

Many people diagnosed with diabetes are required to test their blood sugar levels on a regular basis. Each time you do this, you should log the details in a notebook or on your phone, alongside information about the time, date, and recent activities.

Even if you have a diagnosis of diabetes, that doesn’t mean it is the end of the story. By working with your doctor to achieve good blood sugar control, you can prevent or delay complications that would otherwise affect your kidneys, nerves, and eyes. Remember that diabetes increases your chances of suffering from a stroke or heart disease, but controlling your blood sugar to reach your individualized target is part of the plan to make these issues less likely. Tight blood sugar control can also mean a greater chance of low blood sugar levels, so it is a balancing act. Heed your doctor's advice about how aggressive your goals should be.

The chart below, provided by webmd, will help you manage your blood glucose levels.