Because type 2 diabetes often develops slowly, blood sugar can be raised long before you feel anything. Many people are diagnosed during a routine check or while being investigated for something else. Some only find out after a complication, such as an eye or nerve problem, has already begun.
This silent course is the reason screening is recommended for people with risk factors, including family history, older age, excess weight, high blood pressure, certain ethnic backgrounds, or a history of gestational diabetes.
If any of these apply to you, ask your doctor whether you should be tested even if you feel well. Catching raised blood sugar early gives the best chance to prevent or delay complications through lifestyle changes and, where needed, medication.