A swollen head may be caused by fatigue, intracranial diseases, systemic diseases, psychiatric disorders and other reasons. 1. Fatigue: if the patient does not have enough sleep when the brain is in a state of fatigue due to prolonged study or work, dizziness and swelling of the brain may occur. 2. Intracranial diseases: such as cerebral hemorrhage, insufficient cerebral blood supply, brain tumor, encephalitis, low cranial pressure or high cranial pressure and other diseases, all of which may lead to ischemia and hypoxia of brain tissues, resulting in discomfort such as cerebral swelling. 3. Systemic diseases: if the patient suffers from anemia, hypertension, hyperlipidemia, etc., it may adversely affect the brain function, and the brain bloating may occur. 4. Mental illnesses: such as anxiety disorders, depression, schizophrenia and other diseases, may also cause a feeling of swelling in the head. If you often have a feeling of swelling in the head, it is recommended that you consult a doctor as soon as possible to clarify the cause of the disease.