Simplify the following text for a Grade 8 native English-speaking person.
Original: The causes of nosebleeds can generally be divided into two categories , local and systemic factors , although it should be remembered that a significant number of nosebleeds occur with no obvious cause .
Simplified: Most nosebleeds happen in the front of the nose , and these are called anterior nosebleeds . Sometimes , people get nosebleeds in the back of their noses , called posterior nosebleeds .