Associated Press | Walgreen’s is joining efforts to stem the nation’s diabetes epidemic by offering free blood sugar testing.

The Deerfield-based chain’s 24-hour stores and clinics will offer the tests Friday from 11 a.m. to 7 p.m. People aged 18 and older are eligible.

Also, free diabetes tests will be available at Walgreen’s stores in thousands of communities nationwide through Feb.18.

The announcement came Thursday on Oprah Winfrey’s show, as part of her pitch to attack the epidemic.

Nearly 24 million Americans have diabetes, and an estimated 6 million or so are undiagnosed.

Prevalence has increased dramatically over the past decade, partly because the most common type of diabetes is linked with obesity.