The symptoms of chronic poisoning mainly depend on the cause of poisoning, the different types of poisons in the performance will be different, including heavy metal poisoning, pesticide poisoning and so on. 1. Heavy metal poisoning (1) Chronic lead poisoning can lead to erythrocyte cell membrane and other organelle membrane damage, mainly for the hematopoietic system and digestive system symptoms, such as anemia, hemolysis, abdominal pain, nausea and so on. (2) Chronic mercury poisoning can damage nerve cells, mainly manifested as neuropsychiatric abnormalities, such as depression, agitation, numbness of the mouth and tongue. (3) Chronic copper poisoning is mainly characterized by impaired vision. 2. Pesticide poisoning (1) Organophosphorus pesticide poisoning can lead to neurotransmitter transmission abnormalities, mainly resulting in muscarinic and nicotinic symptoms, such as pinpoint pupils, excessive sweating. (2) Pyrethroid pesticide poisoning is mainly manifested as skin irritation and digestive symptoms, such as abdominal pain, diarrhea. In severe cases, central nervous system symptoms will occur. Therefore, once chronic poisoning occurs, the first thing to do is to clarify the cause of the disease, as soon as possible to remove the residual poison in the body, as well as the early use of detoxification drugs.