Headaches can indicate serious diseases such as craniocerebral lesions, extracranial lesions, systemic diseases and psychosomatic diseases, etc. It is recommended to improve the craniocerebral examination in time to make it clear. 1. Craniocerebral lesions: Infectious diseases such as meningitis, encephalitis, etc., inflammation stimulates the meninges, pulling the meninges to cause headache; vascular diseases such as cerebral hemorrhage, cerebral vascular malformation, etc., which can cause intracranial and extracranial blood vessel constriction, dilation, as well as blood vessel pulling or stretching can lead to headache. In addition, occupying lesions and craniocerebral trauma can also cause headache. 2. Extracranial lesions: neuralgia, such as trigeminal neuralgia, occipital neuralgia, etc., the cerebral and cervical nerves that transmit pain can be stimulated, squeezed or pulled, which can cause headache. 3. Systemic factors: cardiovascular diseases such as hypertension, especially hypertensive encephalopathy, rapid increase in blood pressure can cause cerebral edema or intracranial elevation, and headache. Others, such as acute infections and poisoning, may also trigger headaches. 4. Mental illnesses: such as depression, anxiety, etc., headache can occur in different degrees. When headache symptoms occur, it is recommended to consult a doctor in a timely manner to identify the cause of the headache and then target treatment.