Leukemia can usually drink coffee, but it is recommended to drink a small amount. Specific cases should be analyzed. The following is an explanation of the benefits and harms. 1. The most important ingredient in coffee is caffeine, which can promote the secretion of digestive juices and improve the appetite of leukemia patients. Currently, studies have found that coffee may help to minimize the harm of radiation. 2. However, improper consumption of coffee can cause leukemia patients to lose their appetite. Excessive and prolonged consumption of coffee may also cause insomnia and inhibit calcium absorption. Since leukemia patients, especially those in the chemotherapy stage, may experience nausea, vomiting, and loss of appetite, coffee is not recommended at this stage. Although the caffeine content in coffee may have the effect of promoting digestion and preventing radiation, drinking more of it may also cause loss of appetite and insomnia, so it should be consumed in small amounts and is not recommended during the treatment period. It is recommended that you consult your doctor and drink it under his or her supervision.