Causes of fluid buildup in the brain include obstruction of the flow of cerebrospinal fluid, poor absorption of cerebrospinal fluid and overproduction of cerebrospinal fluid, according to Mayo Clinic. Underlying causes in infants include birth defects, genetic defects and infections during pregnancy, explains Healthline.
Causes of fluid buildup in the brain of infants include bleeding in the ventricles and abnormal development of the central nervous system that leads to an obstruction of the flow of cerebrospinal fluid, explains Mayo Clinic. Infections in the uterus such as syphilis and rubella sometimes cause inflammation of fetal brain tissue, which leads to fluid buildup in the brain.
In people of all ages, causes of fluid buildup include central nervous tumors and infections of the central nervous system such as mumps and bacterial meningitis, states Healthline. Fluid buildup is also caused by bleeding or traumatic injury to the brain, notes Mayo Clinic.
In adults, hydrocephalus or fluid buildup in the brain normally has unknown causes, according to Healthline. However, people with meningitis or bleeding in the ventricles are at a higher risk of fluid buildup in the brain. It is also common among adults who have had head injuries or brain surgery. Blood clots in the brain may block the ventricles and cause fluid buildup in the brain, notes the National Health Service.