A predisposing factor to disease is a substance, event, characteristic or condition that contributes to the disease's onset. It does this by preventing the body from defending itself efficiently.
Predisposing factors also include hereditary conditions and lifestyle factors. For example, common non-modifiable risk factors for heart disease include being male, having a family history of heart disease and being African-American, WebMD states. Modifiable lifestyle factors include smoking, obesity and poorly controlled diabetes. People who want to lower their risk of disease can address their modifiable risk factors. For example, smokers who quit smoking can reduce their risk of heart disease.