After age 35, anyone who is overweight should get a fasting blood glucose test; if the result is normal, repeat it every three years.

A fasting blood glucose test costs just a few dozen yuan. Testing for glycated hemoglobin is a bit pricier, still only a few dozen yuan. All it takes is one blood draw at a clinic.

The US Preventive Services Task Force is the official body that issues screening recommendations in the US. Its current guidance states that adults aged 35 to 70 who are overweight or obese — even with no symptoms at all — should be screened for prediabetes and type 2 diabetes. Overweight is defined as a BMI of 25 or higher, while obesity means a BMI of 30 or higher. This recommendation is rated as a Grade B. The Task Force also explicitly notes: “It is reasonable to screen adults with normal blood glucose levels for prediabetes every three years.”

US Preventive Services Task Force (2021). Screening for Prediabetes and Type 2 Diabetes. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/screening-for-prediabetes-and-type-2-diabetes

Having a prediabetes diagnosis does not mean you must start taking medication right away. Many people can fully reverse this condition simply by making lifestyle changes. In China, only a small fraction of adults are aware they have diabetes; most only find out after developing complications.