Hydrocephalus is an abnormal accumulation of fluid in the subarachnoid space or intracerebroventricular space of the skull that causes abnormal enlargement of part or all of the brain. This is a serious disease that occurs mainly in the newborn population, but it is also important to know that hydrocephalus does not only occur in the newborn population, but also in adults and the elderly, where hydrocephalus is often found. The common symptoms of hydrocephalus are: 1. After birth, the newborn’s head circumference increases rapidly, the head becomes round, the subcutaneous veins become angry, the front and back of the heart bulge, and the tension is high; the cranial sutures separate, the skull becomes thinner, and the skull increases, mainly in the supratentorial part of the cerebellum, and the posterior cranial fossa increases due to four ventricular tumors or four ventricular outlet occlusion; the child’s eyes are downward-looking, and the upper eyelids cannot be lowered with them, called sunset eyes. Further development of hydrocephalus, downward displacement of the brainstem, compression of various nuclei, eye movement disorders and vision loss, etc. 2. Adults mainly show symptoms of high cranial pressure, such as headache, nausea, blurred vision, and edema of the optic nerve papillae. 3. Older people often develop normal pressure hydrocephalus, showing symptoms such as unstable walking, weakness of lower limbs, urinary incontinence, and altered intelligence. Symptoms of hydrocephalus vary in different age groups, so pay attention to differentiation. There is also a difference in the performance of hydrocephalus in the acute and chronic phases. In the case of acute hydrocephalus, it can rapidly cause an increase in intracranial pressure, which can lead to headache, vomiting, and even rapid coma, which can be life-threatening. In the case of chronic hydrocephalus, the symptoms are often chronic increased cranial pressure, which can cause headache, optic papilledema, progressive dementia, unstable gait, and even incontinence. The treatment of hydrocephalus must be timely to avoid aggravation of symptoms, which can easily leave problems even if cured. Therefore, it is important to know more about the symptoms caused by hydrocephalus.