As 'Squire Fullwood' rightly says, Type 2 diabetes will generally take some time to develop, usually anything from a year to several years, making the progression a slow process. For this reason many Type 2's are shocked when at a routen medical examination they are found to be diabetic, as many will have not been aware that their diabetic condition was slowly developing in the background.
At one time Type 2 diabetes was traditionally associated with the older person (usually over 40 year of age) but these days it is slowly encroaching into the younger teenagers, and I know of someone as young a 6 years old having been diagnosed with Type 2 diabetes.
Generally it has become worsened by a seditary lifestyle with little exercise and poor diet (too much JUNK foods, salt, fats & Refined Sugars) and for these reasons it is therefore so important that a Type 2 follows a revised sensible diet together with simple exercise.