How is blood sugar related to type 1 diabetes?

Type 1 diabetes causes blood sugar to become dangerously high. People with type 1 diabetes have little or no ability to produce or use insulin. Without insulin, sugar builds up in their blood instead of going into their cells to be used for energy.

People with type 1 diabetes rely on self-administered insulin injections to keep their blood sugar from becoming too high. They use blood sugar monitors to keep track of their blood sugar levels, so they can plan the right amount of insulin to keep blood sugar levels stable.

People with type 1 diabetes take insulin to bring high blood sugar levels down. But depending on what you've eaten and how recently you've exercised, the insulin may bring your blood sugar down too low. Symptoms of low blood sugar include headache, hunger, nervousness, rapid heartbeat, shaking, sweating and weakness.

High blood glucose—also called hyperglycemia or high blood sugar—occurs when blood sugar levels become too high. Several factors can lead to high blood glucose-including improper medication doses, nutrition, physical activity, stress and your overall treatment plan. Many people with type 1 diabetes experience high blood glucose. If left unchecked, high blood glucose can lead to severe complications.

Low blood glucose—also called hypoglycemia or low blood sugar—occurs when blood sugar levels become too low. This is something that needs to be managed on a daily basis when you have type 1 diabetes. Several things can affect blood glucose levels, including medication, diet, exercise and your treatment plan. For example, eating a snack before bedtime can help prevent nighttime hypoglycemia. Talk to your doctor about what you can do to prevent low blood glucose.