Glucose is a sugar found in the bloodstream that is the body’s main source of energy. It is a simple sugar, meaning it cannot be broken down into other sugars. People obtain glucose by eating foods that contain carbohydrates, such as breads and cereals, vegetables, fruits and sugary sweets. Glucose is also manufactured in the body through the breakdown (metabolism) of protein and fats.

When food is eaten, it is broken down into glucose and absorbed into the bloodstream. As the amount of glucose in the bloodstream starts to rise, an abdominal gland called the pancreas reacts by producing insulin. This natural hormone helps carry the glucose from the bloodstream into the cells of muscle and fat tissue. Inside the cells, glucose – which is made up of carbon, hydrogen and oxygen – is broken down and converted into adenosine triphosphate, better known as ATP. This is the body’s primary fuel. 

Without insulin, glucose cannot be processed and builds up in the bloodstream, a condition called diabetes. This can occur when patients either cannot produce insulin (type 1 diabetes) or have cells that have become resistant to insulin (type 2 diabetes). People with type 2 diabetes may find that their ability to produce insulin also wanes over time.

Medications and lifestyle changes such as nutritious diet, exercise and weight loss help those with diabetes to use insulin more effectively, thus controlling their glucose. This can help patients to live longer and healthier lives.