An official website of the United States government
Here’s how you know
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.
Your blood is living tissue made up of liquid and solids. The liquid part, called plasma, is made of water, salts and protein. Over half of your blood is ...