The seven stages of late-onset encephalopathy are poisoning stage, false healing stage, late-onset encephalopathy stage, exacerbation stage, stabilization stage, and recovery stage. 1. Poisoning stage: Late-onset encephalopathy is caused by poisoning. Carbon monoxide poisoning affects brain tissues and nerves, and this stage is called the poisoning stage. 2. False healing period: After poisoning, the symptoms recover through a period of treatment, and then the uncomfortable symptoms appear again after a few days. 3. Delayed encephalopathy period: As the condition worsens, it affects the brain, resulting in ischemia and hypoxia of the brain, so delayed encephalopathy will appear. 4. Exacerbation period: After the nervous system of the brain is affected, some patients may experience symptoms of exacerbation, resulting in symptoms such as dementia, limb movement disorders or consciousness disorders. 5. Stabilization period: Through a period of treatment, the abnormal symptoms of the brain and nervous system can be effectively relieved, and the condition will gradually recover and stabilize. 6. Recovery period: The condition gradually recovers, which is called the recovery period. 7. Cure period: through regular treatment after the emergence of late-onset encephalopathy, some patients may be cured, but some patients may also have sequelae. Patients with late-onset encephalopathy should go to the hospital for consultation and standardized treatment according to the doctor’s instruction.