Glucose comes from the food we eat. Foods that have carbohydrates are broken down into glucose. This glucose is used for energy. Glucose in the blood is carried to all the cells of the body. However, in order for blood glucose to enter the cell, a special helper and glucose are needed. The helper that glucose needs to enter the cell is insulin. Insulin is a hormone made by the pancreas. Cell receptors are like doorways into a cell. A cell can have many receptors.
To imagine how glucose, insulin, and cell receptors work, think of your car. To park in your garage, you need a garage door and a garage door opener. Glucose is like your car, the cell receptor is like the garage door, and the insulin is like the opener.
If your body does not make enough insulin or if it does not work properly, glucose cannot get into your cells. Instead, glucose stays in your blood causing high blood glucose, or hyperglycemia. People with hyperglycemia have diabetes.