Common causes of hemolysis include: antigen-antibody reaction, infection, use of certain drugs, mechanical injury and so on. 1. Antigen-antibody reaction: Input of incompatible blood will lead to antigen-antibody reaction and destruction of red blood cell membrane, thus leading to hemolysis. 2. Infection: Infection with pathogenic microorganisms such as Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa will destroy red blood cells and shorten the life span of red blood cells, thus leading to infectious hemolysis. 3. Use of drugs: Hemolysis may occur with the use of penicillin, quinidine, clopidogrel and other drugs. 4. Mechanical injury: the squeezing and shearing effect of cardiac and vascular lesions on red blood cells will lead to a decrease in the deformation ability of red blood cells, which will be engulfed by phagocytes and extravascular hemolysis will occur. Patients with hemolysis need to go to the hospital as soon as possible, to clarify the cause of the disease, under the guidance of physicians to treat the cause.