Joyce Hunter-Knox and her colleagues have strapped blood pressure cuffs on thousands of arms and urged countless people with high readings to get help. They believe they have saved some lives.
But Hunter-Knox is not a medical professional. She's a barber who owns a shop catering mostly to African American men in Greenville, Mississippi.
As part of a program run by the state's health department, she is doing her part to fight the nation's bigger killer: cardiovascular disease. The experience has been eye-opening, she says.
Those people have a lot of company. Millions of Americans are walking toward early, preventable deaths because of heart attacks, strokes and related conditions, experts say.