Everything you need to know about blood sugar, plus a helpful chart about the glycemic index.

Why blood sugar is so important, and how it can get out of balance when you have type 2 diabetes

The body works in a delicate equilibrium.

When in balance, we’re healthy and we’re full of energy and feel well. When out of balance, symptoms, and even disease, set in. Nowhere is this more evident than with our blood sugar.

When we talk about blood sugar, we’re referring to what happens after you eat food and it’s digested. The goal of the digestive system is to break down the food you eat into parts small enough for cells throughout the body to absorb and use for energy, growth, and repair. Blood sugar is one of these “parts” that a food is broken down into.

It’s after digestion of food that levels of the simple sugar called glucose normally rise in the blood. (How much a food raises blood sugar is measured by a rating called the Glycemic Index.

Different types of food groups supply cells with different needs. Carbohydrates (sugars, fibers, and starches), in particular, get broken down and turned into glucose. It’s this glucose that’s used as energy by our cells to perform work such as moving your muscles while you walk. Glucose is also a main source of fuel for the brain. How your body manages this glucose determines whether or not you have diabetes.

The role of the pancreas & the liver.

The pancreas is a long, thin, organ that’s located in the abdomen behind the stomach. It’s this digestive organ that’s responsible for breaking down carbohydrates, as well as fats and proteins, for use by the body’s cells.

The pancreas is also important because it produces hormones called insulin and glucagon. When glucose rises in the bloodstream after a meal with carbohydrates, the pancreas senses this rise and produces insulin. Insulin removes glucose from the bloodstream and moves it into the cells of the body where it can be used for energy. When this happens, blood levels of glucose naturally drop, triggering the pancreas to switch off the release of insulin. This is not what happens, however, when you have diabetes.

The liver also plays a key role in the regulation of blood sugar. This digestive organ, about five inches in length, is located in the upper righthand side of the body. The liver is in charge of many esssential functions in the body but when it comes to blood sugar, it has one extremely important role: when working optimally, and when signaled by the hormone insulin, it converts excess glucose in the blood after meals (whatever the cells can’t use right away) into something called glycogen and stores it.

Then, when signaled by the hormone glucagon (produced by the pancreas), the liver converts the stored glycogen back into glucose and releases it into the bloodstream for use by cells during times of fasting (e.g., when you’re sleeping at night).

Together, the pancreas and the liver work together to keep levels of glucose balanced in the body.When this process is disrupted and doesn’t work as it should, glucose levels get out of balance in the blood and begin to rise. Symptoms and insulin resistance, prediabetes, and diabetes can develop as a result.

How type 2 diabetes starts

Type 2 diabetes begins years earlier with a silent and often symptomless condition called insulin resistance. This occurs when the cells in your body become less sensitive to sugar found in the blood and, as a result, these cells may begin to stop responding to insulin and will stop taking up glucose from the blood.

You may recall that insulin is the pancreas-secreted hormone that triggers glucose in the blood to move into cells. This occurs either after a meal or during times of fasting when the liver converts glycogen to glucose. In insulin resistance, if the glucose cannot move into the cell, it will remain in the bloodstream and the cells won’t be able to use this glucose as a source of energy.

To compensate, the pancreas keeps pumping out insulin in a desperate attempt to get the cells to respond. If the lifestyle conditions that triggered this situation in the first place don’t change, two things happen: sugar in the blood rises and stays high and the pancreas eventually gets “tired” and can’t keep up the pace of continually pumping out insulin without an adequate response. This is when prediabetes and diabetes begins.

The causes of insulin resistance are the same for prediabetes and type 2 diabetes: being overweight or obese, having visceral or belly fat (which triggers chronic inflammation and affects the liver’s ability to efficiently store glucose), leading an inactive lifestyle, and regularly eating a diet high in processed sugar and carbohydrates.

The next step up in the progression to diabetes is prediabetes, where blood sugar levels are higher than normal— and often higher than if you had insulin resistance—but not high enough to be diagnosed with diabetes. At this stage, symptoms similar to full-blown diabetes begin to manifest as the body desperately tries to get rid of the excess sugar in the blood and maintain its equilibrium: increased thirst and frequent urination (an attempt by the body to get rid of the excess glucose), excess hunger (the muscle cells aren’t getting enough energy so they’re putting out a call for more food), fatigue (your cells aren’t getting enough fuel for energy), and blurred vision (high blood sugar causes the lenses to swell).

An estimated 60 to 70 million Americans have insulin resistance, while more than 100 million have prediabetes (more than 80 percent aren’t aware they have it), and more than 37 million have diabetes. This is why it’s important to have your blood sugar levels tested at your annual physical if you’re overweight or obese, have belly fat, are physically inactive, and have diabetes in your family.

A continued high level of glucose in the blood can, over time, cause damage in the body including to:

The Eyes

Diabetes is a leading cause of blindness.

The nerves and blood vessels

High glucose levels can damage the blood vessels that bring critical oxygen to the body. This results in stiff blood vessels to/from the heart, which are more prone to blockages (increasing your risk of heart disease). It can also cause poor circulation overall, as well as damaged nerves that stop sending pain signals. This is why diabetes, if it continues to progress, can lead to amputation of the feet, fingers, and/or limbs.

The Kidneys

Having too high glucose levels over time can result in poor circulation to the kidneys, which become unable to properly filter out fluid and waste (their main job), leading to kidney disease and failure. This is why diabetes is the number one cause of kidney failure.

Diabetes can also be fatal; it’s the seventh leading cause of death in the United States, according to the Centers for Disease Control and Prevention. This is why it’s vital to catch and treat diabetes as early as possible.

It’s important to realize though that you can change the trajectory of your disease. Making lifestyle changes
now and taking medication, can and does make a difference. The worst is not inevitable.