Cerebrospinal fluid (CSF) is commonly caused by traumatic injury, but also non-traumatic injury can cause CSF. CSF is characterized by a clear, bloody fluid coming out of the ear or nasal cavity. If it flows into the mouth with a slight salty taste, it is important to avoid infection and not to cough violently. If the neck receives pressure or when the head is bowed, more fluid comes out. And because of the cerebrospinal fluid outflow can lead to a decrease in intracranial pressure, which can lead to symptoms such as dizziness and headache. Cerebrospinal fluid is a colorless and transparent fluid, so by analyzing the fluid coming out of the nose and ears, the color and smell, and combining it with the clinical manifestations, you can determine whether it is caused by cerebrospinal fluid outflow. Cerebrospinal fluid effusion can also cause memory loss, limb inflexibility and many other serious symptoms, so it is necessary to consult a doctor in time for examination and treatment, and it is recommended to check the CT of the brain for a clear diagnosis.