Why are women often carriers of x-linked traits but rarely affected by them?

Most X-linked conditions are recessive. This means that in a person with two X chromosomes (most females), both copies of a gene (i.e., one on each X chromosome) must have a change or mutation whereas in a person with one X chromosome (most males), only one copy of a gene must have a mutation. A female with a mutation in one copy of a gene on the X chromosome is said to be a “carrier” for an X-linked condition