In some cases, when someone who is intersex is born, the doctors are unsure of if they physically look like a boy or a girl. In other cases, people who are intersex may have the body parts of a boy or a girl at birth, but may go through puberty differently, and find out they are intersex around puberty.
Often people who are intersex need medical treatments so that they can go through puberty or for other reasons. About 1 in 100 people is intersex. This is about 3.8 million people in the United States!
Again, this is important to note: being intersex is different from being transgender. People who are intersex have bodies that are physically different than we would usually expect with a girl or a boy.
Being transgender has to do with how someone feels about their gender. There are some studies that suggest that some people who are intersex may be more likely to be transgender. This depends a lot on the genetic condition.
About 1 in 200 people identifies as transgender in the United States. That is 1.4 million people just here in America!