Disease registries contain information about cases of specifically diagnosed illnesses (for instance, cancer) or, in some instances, on self-reported illnesses. The data might be available only on those people who have died from the disease (mortality data) or on people who have the disease (morbidity data), or for both.
For information on chronic diseases (including cancer, sexually transmitted diseases, asthma, etc.) visit the Mortality Data from the National Vital Statistics System Website, and the CDC WONDER Website.