Mold or mildew on bathroom ceiling?

my bathroom has a green mold or mildew on the ceiling. I believe this is because of ventilation problems. The bathroom is oretty big with only one window which is located toward the end. has no ceiling fans, and sometimes people in my family even close the windows while having hot steaming showers. now theres green mold or stuff on the ceiling. i cleaned it with bleach but i got some of the bleach liquid that i was using to clean it with on my self. i just wanted to know is this mold dangerous is it comes in contact