Nearly 185,000 Gwinnett County residents, about 24 percent, have no health insurance, recent data shows.

The county of nearly 900,000 people – one of the largest in the state – has a worse uninsured rate than some other metro Atlanta counties, including Fulton and DeKalb. Without insurance, people often go months or years without getting the medical care they need — suffering from diabetes, heart disease and other chronic illnesses that can turn deadly if not treated.

The annual County Health Rankings & Roadmaps project was created by the Robert Wood Johnson Foundation and University of Wisconsin Population Health Institute. The study provides a snapshot of a community's overall health. It looks at health measures, such as rates of obesity and smoking, access to medical care, long commute times and sexually transmitted diseases.