Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Hydrocephalus ?
    ### Response:
    Hydrocephalus is the buildup of too much cerebrospinal fluid in the brain. Normally, this fluid cushions your brain. When you have too much, though, it puts harmful pressure on your brain.    Hydrocephalus can be congenital, or present at birth. Causes include genetic problems and problems with how the fetus develops.
    