Sometimes a sudden headache may be caused by overwork, herpes simplex virus infection, nerve demyelination, intracranial lesions and so on. 1. Overexertion: tension headaches can be caused when the body is overworked and can take many forms, resulting in a stabbing headache that clears up after a while. 2. Herpes simplex virus infection: Herpes simplex virus infection often causes nerve pain, mainly because the herpes simplex virus infection is often latent in the place of the nerve root, when the body’s immune function decreases, it will stimulate the surrounding nerves, thus causing a sudden tingling headache. 3. Nerve demyelination: nerve demyelination causes electrophysiological short circuits between nerve fibers, and there will be excessive nerve discharges, resulting in the phenomenon of tingling in the head, which may be tingling for a while, or tingling for more than ten minutes. 4. Intracranial lesions: intracranial tumors, embolism, hemorrhage and other diseases, due to transient ischemia and hypoxia and other factors, can also cause headache and a good situation. It is recommended that patients with sudden headache should go to the hospital for examination in a timely manner to clarify the cause of the problem and actively treat it under the guidance of the doctor.