Most patients with multiple myeloma develop recurrent lung infections, urinary tract infections, skin infections and herpes zoster early or during the course of the disease, and are more difficult to treat than normal. Studies from Sweden have reported that more than one in five patients with multiple myeloma die from infections within one year of diagnosis. To be exact, within one year of diagnosis, 22% of multiple myeloma patients died from infection-related causes. Overall, patients with multiple myeloma had a seven-fold higher risk of infection than those in the drug-controlled control group. This risk is almost 12 times higher in the first year after diagnosis. Why are patients with multiple myeloma prone to co-infection? There are several main reasons: 1. Humoral immune deficiency: Patients with myeloma have decreased immunity due to the elevation of a large number of abnormal immunoglobulins leading to a decrease in normal immunoglobulins. 2.Longer hospitalization: There are many bacteria in the environment of the ward. If the hospitalization time is too long, many bacteria that do not have pathogenic effect on normal people (conditional pathogens) will become pathogenic at this time under the condition of lowered immunity, leading to the occurrence of infection. 3, neutropenia: the disease itself or chemotherapy can lead to neutropenia, the longer the neutropenia lasts the higher the probability of infection. 4, chemotherapy: basically all chemotherapy drugs can cause a decrease in immunity, increasing the risk of infection. 5.Long-term application of hormone: For the treatment of myeloma, glucocorticoid is a very important drug, and almost all the protocols contain glucocorticoid. And long-term application of hormones greatly increases the risk of infection. In addition, patients with myeloma often have pathological fractures, are bedridden for a long time, and are prone to skin infections, or crushing pneumonia, etc. Therefore, it is recommended that patients with multiple myeloma can be vaccinated and encouraged to perform activities that prevent infections from occurring. If signs of infection such as fever appear, promptly visit the hospital for timely treatment.