Benign intracranial hypertension: Increased pressure within the brain in the absence of a tumor. Symptoms may include headache, nausea, vomiting, pulsating intracranial noises, singing in the ears, double vision, loss of visual accuracy, and even blindness. It is most common in women between the ages of 20 and 50. The cause is usually not known. The condition is associated sometimes with the use of tetracycline, nalidixic acid, nitrofurantoin, phenytoin, lithium, and amiodarone, and the overuse of vitamin A. Diagnosis is by brain imaging and lumbar puncture. Drugs to reduce cerebrospinal fluid production or hyperosmotic drugs may be used to reduce fluid buildup. Excess cerebrospinal fluid may be removed by repeated spinal taps, shunting or a type of surgery called optic nerve sheath fenestration that allows the excess fluid to escape. Steroids may be prescribed to reduce swelling of brain tissue. Benign intracranial hypertension is also called pseudotumor cerebri.