The timing of symptoms of mercury poisoning is directly related to the level of mercury intake in a short period of time, and can have acute symptoms or manifest as chronic poisoning symptoms. Mercury is the most toxic heavy metal pollutant, is volatile, and is mainly toxic by inhalation. Chronic mercury poisoning often manifests as mental abnormalities, inflammation of the gums, tremors, chest pain, cough, and nausea, vomiting, abdominal pain, and diarrhea, usually related to the form, route, dose, and timing of mercury entry into the body. Mercury also has significant neuronal destruction, brain atrophy and cortical loss. If the concentration of mercury inhaled for a short time is >1.2mg/m3, when acute mercury poisoning occurs, the symptoms of mercury poisoning usually appear within 5 hours; if the concentration of mercury inhaled is ≤1.2mg/m3, the onset of mercury poisoning will be about 1-4 weeks, which varies from person to person. Mercury agents that can be exposed to in daily life include mercury thermometers, mercury-exposed rice, mercury-exposed aquatic products, etc. Attention should be paid to their own protection, and medical treatment should be sought immediately after symptoms of poisoning appear to reduce mercury poisoning damage.