Managing Diabetes: Understanding Diabetes Diabetes is a lifelong disease. When you have diabetes, your body cannot properly use the energy from the food you eat. Using food for energy is as important to your health as having air to breathe. When You Eat, What Should Happen in Your Body? When food enters the stomach, it breaks down into a form of sugar, the body's main source of energy. The sugar enters the bloodstream and the level of sugar in the blood begins to rise. The pancreas senses the increase in blood sugar. The pancreas makes insulin (a hormone), and sends it into the bloodstream. Insulin lowers the level of blood sugar by allowing the sugar to leave the bloodstream and enter the cells, causing the blood sugar level to decrease. The body's cells use the sugar for energy. When this process occurs as it should, you have the energy for a full and active life. And if This Does Not Happen? In people with diabetes, this system of converting blood sugar into energy does not occur properly, and sugar builds up in the bloodstream instead of going into the cells of the body. If too little insulin is available, the blood sugar level can rise even if you have not eaten. Without enough insulin to keep blood sugar levels in check, the body can make extra sugar and release it into the bloodstream. This can happen anytime insulin is in short supply or is not doing its job, often when the body is under excess stress, as in an injury or illness.