Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The interaction between external factors such as environment, infection, injury, toxicity, and genetic factors causes disease
Not included are allergens, which can be derived from various sources. The red cross marks a genetic disease variant, inherited or acquired.
