Blood cancer refers to leukemia, and its early symptoms may manifest as fever, bleeding, infection and so on. 1. Fever is an early symptom of leukemia, which may manifest as low fever or reach high fever, 39~40 degrees or higher, and patients are often accompanied by chills, sweating and other such symptoms. 2. Bleeding: patients with early bleeding symptoms account for about 40% of the patients, skin bleeding, nosebleeds, gum bleeding, and some show excessive menstrual bleeding, intracranial bleeding can be headache, vomiting and even death. 3. Infection: leukemia patients are easy to be infected by viruses and bacteria because of the decline of disease resistance, and some of them may cause sepsis and even lead to death. Patients with these symptoms should actively consult the doctor, do not delay the condition, do not self-medication.