What causes sudden hydrocephalous in a healthy 46 yr old female and what r the presenting symptoms and treaement?

Several reasons. Hydrocephalus is a buildup of cerebrospinal fluid (CSF) in the brain. If it occurs suddenly, there is usually a cause like tumor, obstruction, infection, cancer, hemorrhage, or substance that causes chemical coating of the absorptive cells so that spinal fluid builds up. There are of course several more reasons. Treatment could be shunting or correcting the cause of the hydrocephalus.
Go to the doctor. Something is blocking the normal circulation of the cerebral spinal fluid csf. It could be a tumor. Causes headaches, visual or balance changes. You need a ct scan and a neurological evaluation asap.