Leukorrhea is the official term for a common phenomenon: thick yellow white discharge from the vagina. In the Netherlands it’s called “white flood”.
Many girls get it for the first time in their early teens, often before they have their first period. It’s caused by a surge of estrogen and might be the first sign puberty is on its way.
Some girls have hardly any discharge, but others to such a degree that it leaks through their underwear. In that case a girl can wear panty shields.
Leukorrhea is completely normal. It’s a sign that the vagina is healthy, cleaning itself all the time. This white fluid has an acidic quality that fights vaginal infections.
Discharge can also be caused by a vaginal infection or a STD. If that’s the case the amount of discharge often increases, the structure changes and it might smell bad. Go to your GP if you suspect something is wrong.