Type 1 diabetes, which used to be called insulin-dependent diabetes or juvenile-onset diabetes, usually occurs in children or younger adults, but it can occur at any age. About 5% - 10% of people with diabetes have type 1.
In Type 1 diabetes the body does not make insulin. Insulin is needed to get glucose from the food you eat into the cells where it can be used for energy. In the absence of insulin, glucose builds up in the blood stream.
If you have Type 1 diabetes you have to take insulin to manage your blood glucose levels. Following a healthy meal plan and staying active will help you manage your diabetes. Checking blood glucose gives you the information you need to work with your diabetes care team to stay healthy.
NHS UK, 2012: http://www.nhs.uk/Conditions/Diabetes/Pages/Diabetes.aspx